CD274 and nonpapillary renal cell carcinoma: If we accept the hypothesis that release of soluble T‐cell suppressor molecules is a mechanism by which tumors interfere with systemic antitumor immunity, it is also important to determine whether the serum levels of soluble T‐cell regulatory molecules (such as PD‐L1, B7‐H4, PD‐1, and CTLA‐4) can be used as biomarkers to predict the effectiveness of immunotherapy targeting T cells in patients with ccRCC.