PETHEMA (Programa de Estudio y Tratamiento de las Hemopatías Malignas) was born in 1973, in a Spanish city called Zaragoza. The meeting in Málaga en 1993, upon the 20th aniversary of the institution, was crutial for a generational renovation. Currently, PETHEMA is involved in a explosive neverending moment of growing and bigger development of several research lines. PETHEMA is the main cooperative research group of Spanish Hematology, son of the Spanish Society of Hematology and Hemotherapy (SEHH). Led by hematologists and other specialists of this area of Medicine, it develops, through his private research foundation (PETHEMA Foundation for the treatment of Leukemia and Lymphoma) a big amount of studies of basic and clinical research of several sort in the field of Hematology and Hemotherapy . PETHEMA is composed of diverse specialized groups in the different fields of the specialty (MM GEM Group, LAM Group, LAL Group, LLC Group, Bone Marrow Insufficiency Group, etc.)