CD8A and cholangiocarcinoma: Instead of CD8, CD103+ resident-like tumor-infiltrating T cells have been reported as a subtype of tissue-resident memory T cells (TRM) that have been found in the tumor microenvironment [19, 20] and have been shown to have a prognostic effect across multiple types of solid cancers, including cervical cancer [21], head & neck squamous cell carcinoma [22], lung and bladder cancer [23], cholangiocarcinoma [24], gastric cancer [25], ovarian cancer [26], esophageal squamous cell carcinoma [27], colorectal cancer [28], and melanoma [20].