Interestingly, the GAGE2, CCT4, and PRAME cancer/testis antigens were revealed to be correlated with the prognosis for ovarian cancer patients for the first time, while a high expression of the CT45 cancer/testis antigen was already identified as a prognostic factor in ovarian tumors [33,34] as well as in other cancer types, such as lung cancer, breast cancer, gastric tumors, myeloma, Hodgkin’s lymphoma, and fibrosarcoma [10,35,36,37,38,39]. Here, CCT4 is linked to lung cancer.