Despite the existence of null CTECs in carcinoma patients, some CD31+/CD45– CTECs expressing various TMs, such as HER2, PD-L1, and EpCAM, were detected by the integrated strategy of “subtraction enrichment-immunostaining-fluorescence in situ hybridization (SE-iFISH)” (Cytelligen, USA) [11,14,76] in varieties of cancer patients [11,12,13]. The gene discussed is PECAM1; the disease is cancer.