ABCB1 and nonpapillary renal cell carcinoma: In agreement with these findings, we observed protective effects of ABCB1 expression on survival in ccRCC (logrank P = 1.4*10–6, HR 0.49, CI 0.36–0.66) and HNSCC (logrank P = 9.6*10–5, HR 0.59, CI 0.43–0.74; Table 1).