ERBB2 and breast cancer: Recent research has also demonstrated the prognostic value of TILs in certain breast cancer (BC) subtypes such as HER2-positive (HER2+)8–10 and in particular, triple-negative breast cancer (TNBC)7, 11, 12, where the presence of higher levels of TILs in primary tumors was found to correlate with better disease free and overall survival11–14.