A “major milestone” has been reached in the goal of mapping all the cells in the human body, researchers say.

It is hoped that charting the types and properties of all human cells – to build a reference map of the healthy human body – will help experts to better treat diseases such as cancer, diabetes and arthritis.

More than 40 studies are being published that represent a leap in understanding of the cells – the fundamental units of life – in health and disease.

The studies include revealing how the placenta and skeleton form, changes during brain maturation, lung responses to Covid-19, and many more.

This is a major milestone that marks a great leap in our understanding of the human body

Dr Aviv Regev co-chairwoman of the Human Cell Atlas (HCA) consortium, explained that as well as satisfying basic human curiosity, the research is vital for treating disease.

She said: “Cells are the basic unit of life, and when things go wrong, they go wrong with our cells, first and foremost.

“Once we have this map, there are many, many things that we are able to do.

“We are able to better find the causes of disease and understand how they operate.

“We need this map when we try to actually develop new medicine.

“And if we don’t know what the cells look like and what the healthy state looks like, we cannot actually revert a disease cell into a healthy cell.”

Commenting on the publication of the research, Professor Sarah Teichmann, co-chairwoman of the HCA consortium, said: “This is a major milestone that marks a great leap in our understanding of the human body.”

She added: “By creating a comprehensive reference map of the healthy human body – a kind of ‘Google Maps’ for cell biology – it establishes a benchmark for detecting and understanding the changes that underlie health and disease.

“This new level of insight into the specific genes, mechanisms and cell types within tissues is laying the groundwork for more precise diagnostics, innovative drug discovery and advanced regenerative medicine approaches.”

Some 3,600 HCA members from across the world have worked together to profile more than 100 million cells from more than 10,000 people, and some of the results are now being published in Nature and other Nature Portfolio journals.

In one paper, led by researchers in the National Heart and Lung Institute at Imperial College London and the Cambridge Stem Cell Institute at the University of Cambridge, scientists have for the first time identified and mapped the different types of blood vessels.

There are nearly 100km of blood vessels – veins, arteries and capillaries – in an adult human body, which are essential for delivering oxygen and nutrients to organs and tissues while removing waste products.

The study, published in Nature Medicine, uncovered many more different vessel cell types than were previously known.

It is hoped the information will enable treatments tailored to target specific organs and tissues, making treatments for diseases of the heart and blood vessels, as well as conditions where blood vessels play a key role, such as cancer, diabetes, and inflammatory diseases.

Co-first author, Sam Barnett at the National Heart and Lung Institute, Imperial College London, said: “Now, we have a more complete understanding of the molecular and cellular architecture of vessels, and that could allow the creation of drugs that precisely target specific vascular cells in diseased organs and tissues.”

He added: “For example, if scientists want to make a drug that targets blood vessels in the brain, they can now distinguish those cells from other organs’ vessels, enabling them to produce a medication that only affects the intended ones and reduces unwanted side-effects.”

Dr Michela Noseda, a co-lead author on the study, said: “This atlas of healthy blood vessel cells represents a fundamental reference, helping scientists to understand the changes occurring in blood vessels in a wide range of diseases, such as hypertension, diabetes, cancer and heart disease.”

Professor Metin Avkiran, director of international partnerships at the British Heart Foundation said the research provides a “never-before-seen view of our blood vessels”.

He added: “By improving our understanding of the different cell types within our circulatory system, this research can help to accelerate the development of new, targeted treatments for some of the world’s biggest killers, such as heart disease and stroke.”

In another study, published in the Nature journal, researchers created the first blueprint of how the skeleton forms, shedding light on the process of arthritis, and highlighting cells involved in conditions that affect skull and bone growth.

Researchers from the Wellcome Sanger Institute and collaborators used cutting-edge techniques to identify all the cells and pathways involved in the early stages of skeletal development.

They suggest this resource could be used to investigate whether current or future drugs could disrupt skeletal growth if used during pregnancy.

Dr Jan Patrick Pett, co-first author from the Wellcome Sanger Institute, said: “Having a clearer picture of what is happening as our skeleton forms, and how this impacts conditions such as osteoarthritis, could help unlock new treatments in the future.”

The global Human Cell Atlas consortium is developing and using experimental approaches to create comprehensive reference maps of all human cells as a basis for both understanding human health and diagnosing, monitoring, and treating disease.

Researchers are currently working to assemble a first draft Human Cell Atlas by 2026, which will eventually grow to include up to billions of cells across all organs and tissues.