The characterization of the genomic features of 13 MPCs showed that the gains of 1q, 8q, 12q, and 20q and the losses of 1p, 8p, 13q, 16q, and 20q were more prevalent in MPCs than they were in ICD-NOS; recurrent mutations affected genes of the mitogen-activated protein kinase family (MAP3K1, MAP2K6, and MAP3K4); a constellation of the mutations found in MPCs largely corresponds to those typically observed in luminal B cancers (PIK3CA, TP53, ATRX, and CSMD2) [234]. The gene discussed is MAP3K1; the disease is cancer.