In the mid-19th century, they were first observed as small spheres in the blood, and by the turn of the century, their function in blood clotting, known as haemostasis, and the development of thrombosis were discovered. A few years later, the site of their formation in the bone marrow was also identified, where platelets are shed from their giant precursor cells, the megakaryocytes. 

The biology of these small, nucleus-free cells, which are only one-thousandth of a millimetre in size and of which we have about 250 million in every millilitre of blood, has gradually evolved into a major research area.

It has become obvious that platelets have a plethora of functions beyond stopping bleeding or triggering heart attacks. As modulators of the immune system, they also drive inflammatory processes and thereby promote tissue damage in many disease settings.