ESR1 and neoplasm: Evaluation of tumor-infiltrating lymphocytes (TILs) on both hematoxylin and eosin (H&E) stained and immunohistochemical stained tumor sections has demonstrated promising value as a predictor of pCR and survival after neoadjuvant therapy, especially in patients with estrogen receptor (ER)-negative and HER2-positive disease [5–7], and efforts are being made for harmonization of this parameter by a dedicated international TIL-working group [8–10].