A 2020 meta-analysis13 of 52 studies including 27 895 patients found the highest rates of pCR in human epidermal growth factor receptor 2 (HER2)-positive tumours at 36.4 (range 17.5–74.2) per cent, and triple-negative breast cancer (TNBC) at 32.6 (20.3–62.2) per cent. This evidence concerns the gene ERBB2 and neoplasm.