Firstly, immunohistochemical staining showed that for the BCAM protein in 12 ccRCC tumor tissues and 3 normal renal tissues, BCAM protein could be detected in all three normal tissues with moderate intensity and 75–25% quantity in membrane and cytoplasm of renal tubules, but was almost (11 of 12) undetectable in ccRCC tumor tissues (Fig. 1D). Here, BCAM is linked to nonpapillary renal cell carcinoma.