May play a role as a scaffolding protein that may be associated with the abnormal phenotype of leukemia cells. Isoform 2 may possess an antiapoptotic effect and protect cells during normal cell survival through its regulation of caspases. Interacts with PTPN11. Isoform 2 interacts with HIV-1 VPR. Interacts with NOD2 (PubMed:27812135). Ubiquitous with high expression in cervix, spleen and brain. Expressed in hematopoietic cells with increased expression in leukemia cells. Isoform 2 is highly expressed in spleen with almost no expression in muscle and brain. Belongs to the mask family. Truncated N-terminus. Truncated N-terminus.