Within the immature T-ALL leukemias, the early T-cell precursor ALL (ETP-ALL)—defined by the absence of CD1a and CD8 immunomarkers and the presence of stem cells or myeloid markers such as CD117, CD34, HLA-DR, CD13, CD33, CD11b, and CD65 [24], together with negative or dim CD5 expression, defined as expression in <75% of the blasts; rarely presents CDKN2A/B deletions and NOTCH1/FBXW7 mutations [25,26,27]. The gene discussed is KIT; the disease is acute lymphoblastic leukemia.