CD27 and cancer: The higher expression (i.e., above the median expression cutoff values) of each of the six genes – CD27, CEACAM1, CTLA4, LRIG1, PD-L2, and TNFRSF18 significantly associated with the prolonged overall survival in TCGA patient cohorts, giving low hazard ratio (HR) values significantly less than 1 (ranging from 0.44 to 0.91) across different cancers.