The proto-oncogene KIT encodes the type III receptor tyrosine kinase c-KIT, which plays a crucial role in several malignant neoplasms, including gastrointestinal stromal tumors (GISTs), chronic myeloid leukemia (CML), mastocytosis, melanoma, and germ cell tumors. This evidence concerns the gene KIT and chronic myelogenous leukemia, BCR-ABL1 positive.