c-Abl is the human cellular homolog of a the v-Abl viral oncogene. v-Abl was originally discovered as a mouse cell-derived sequence in the genome of the Abelson murine leukemia virus (A-MuLV), a transforming retrovirus isolated by the laboratory of Dr. H.T. Abelson. c-Abl is a tyrosine kinase from the Src-family of tyrosine kinases that localizes to both the cytoplasm and nucleus. It bears an SH2 (src-homology 2) and SH3 (src-homology 3) domain responsible for mediating c-Abl protein-protein interactions. c-Abl is implicated to play a role in multiple cellular processes such as cell cycle checkpoint signaling, apoptosis, cell differentiation, cell adhesion, and transcriptional regulation. Chromosomal translocations involving the c-Abl gene are associated with human leukemias.