PML and acute promyelocytic leukemia: In the subsequent studies PML protein levels were identified to be down-regulated (complete or partial loss) in a wide spectrum of human cancers, beyond APL, including additional hematological neoplasms: non-Hodgkin lymphomas (77%), carcinomas of the: prostate (92%), lung (58%), colon (47%); and breast (53%); tumors of the central nervous system (CNS; 73%) and germ cells (85%) (Gurrieri et al., 2004a); stomach (Lee et al., 2007), lung small cells (Zhang et al., 2000); and sarcomas of the soft tissues (Vincenzi et al., 2010).