In a molecular subtype-adjusted analysis of 91 genes in non-pretreated primary tumors of 156 IBCs and 197 stage 3-4 non-IBCs, 17 genes were more frequently mutated in IBC, including – in decreasing order of frequency in IBC - TP53, NOTCH2, MYH9, BRCA2, ERBB4, POLE, FGFR3, ROS1, NOTCH4, LAMA2, EGFR, BRCA1, TP53BP1, ESR1, THBS1, CASP8, and NOTCH1. This evidence concerns the gene NOTCH4 and inflammatory breast carcinoma.