May mediate the transduction of intracellular signals. Interacts with tyrosine-phosphorylated EPOR and INPP5D/SHIP1 (PubMed:11443118). Interacts with DOCK2 and DOCK5 via its first SH3 domain (PubMed:12393632, PubMed:19004829). Interacts with phosphorylated CBLB and IRS4 (PubMed:10022120, PubMed:9614078). Belongs to the CRK family.