CRK and gastric cancer: Among them, we decided to focus on the CRKL gene at chromosome 22q11.21, the product of which is an SH2 and SH3 domain-containing adaptor protein that shares homology with the CRK oncoprotein, because CRKL is a known substrate of BCR-ABL kinase in Philadelphia chromosome-positive leukemia [27,28] and its role in gastric cancer has not been previously analyzed.