CD81 and cancer: Table 1 summarizes the baseline characteristics of the validation cohort. The median age of the patients was 68 years (range, 28–85 years). Positive CREBBP expression was significantly associated with adverse pathological characteristics, including multifocality, LVI, and higher T stage, whereas high CD81 expression was significantly associated with favorable pathological characteristics, including less carcinoma in situ, less LVI, papillary morphology, and lower T stage (Table 2).