ERBB2 and triple-negative breast carcinoma: As shown in Fig 2, ICOS demonstrates significant overexpression in triple-negative breast cancer (TNBC) patients, as well as in the basal-like and HER2+ subtypes in the TCGA cohort (Fig 2A and 2C), which is also well validated in the METABRIC cohort (Fig 2B and 2D).