CD28 and nonpapillary renal cell carcinoma: Our results showed that the HCST was positively correlated with the expression of CD80 in ccRCC (cor = 0.518, p = 7.21e-38, respectively); the HCST was positively correlated with the expression of CD86 in ccRCC (cor = 0.545, p = 1.57e-42, respectively); the HCST was positively correlated with the expression of CD28 in ccRCC (cor = 0.616, p = 5.85e-57, respectively) (Figure 10B).