ERBB2 and neoplasm: However, the first version of the HER2DX had three major limitations: 1) TILs in HER2DX are measured as a continuous variable (i.e., 0 to 100%) and the scoring of TILs suffers from difficulties of reproducibility across pathologists, 2) only 55 tumour genes were evaluated, and few were immune-related, and 3) HER2DX does not provide information regarding the likelihood of achieving a pathological complete response (pCR) following neoadjuvant anti-HER2-based therapy.