Tumor-infiltrating lymphocytes (TILs), which correlate strongly with T-cell expression signatures, have been significantly associated with higher pCR rates and EFS in multiple ERBB2/HER2-positive neoadjuvant studies.7,8,15,16,17,18,19,20,21,22,23,24,25 In a recent analysis, immune gene signatures appear more valuable than TILs in pCR prediction.26 Another important finding is that immune signatures and TILs are associated with both higher pCR rates and longer EFS, unlike intrinsic subtypes, which often work in opposite directions for predicting response and survival.8 The gene discussed is ERBB2; the disease is neoplasm.