PIM1

null PIM1 is a constitutively active serine/threonine kinase whose abundance is controlled mainly by transcription and protein turnover rather than by activation-loop phosphorylation. Induced downstream of JAK-STAT signaling by cytokines such as IL-3 and FLT3 ligand, it supports hematopoietic cell survival and proliferation by phosphorylating BAD, 4E-BP1 and other substrates, and it stabilizes MYC protein. PIM1 was originally identified as a proviral integration site that collaborates with MYC in murine lymphomagenesis, and it is overexpressed in AML, prostate and pancreatic cancers. Broad-spectrum PIM inhibitors have entered clinical trials for hematologic malignancies and solid tumors.