Background: MerTK/c-mer is one of three members (Tyro3, Axl, and MerTK/c-mer) of the Tyro 3 subfamily of receptor tyrosine kinases (RTK). MerTK/c-mer was cloned from a human B-lymphoblastoid cDNA library. MerTK/c-mer Expression is absent in normal lymphocytes but is found to be ectopically expressed in lymphoblasts and in T-cell ALL cell lines. When activated MerTK/c-mer transmits antiapoptotic and transforming signals and may play a significant role in T-cell leukemogenesis.