A variety of mutations in the gene encoding the proto-oncogene KIT were found in different types of human cancer, in gastrointestinal stromal tumors (GISTs) [30], acute myeloid leukemia (AML) [31], mast cell leukemia (MCL) [32] and human germ cell tumors [33], among others. The gene discussed is KIT; the disease is testicular germ cell tumor.