[Adolfo Ferrata: a brief biographical sketch].

Adolfo Ferrata (1880-1946) was an Italian clinician who, during his scientific life, made a number of significant original contributions to haematology and immunology. He supported the hypothesis that the blood elements originate from a stem cell, the haemocytoblast and, furthermore, that this cell is generated from a least differentiated totipotential element which he called haemohistioblast (reticuloendothelial cell) also known as Ferrata's cell, the real common starting point of haematopoiesis. He thus became the paladin of the monophyletic theory of the origin of the blood cells, a concept which has obtained substantial confirmations in the last years. Moreover Ferrata, in 1907, was the first to demonstrate that the complement could be divided in two inactive components, which could regain the full activity when reunited. This was a pivotal study in the, at the time, new field of immunology. As professor of medicine at the University of Pavia, Ferrata founded an important haematological school (among his pupil was Giovanni Di Guglielmo who gave his name to "Di Guglielmo disease").