BSND and renal cell carcinoma: On the other hand, immunohistochemical analyses using antibodies to the other 2 proteins, BSND and ATP6V1G3, showed specific immunohistochemical signals in the membrane and cytoplasm of the tumor cells; BSND was preferentially expressed in the cell membrane in almost all the BSND-positive RCC cases, while ATP6V1G3 was expressed nearly equally in both the cell cytoplasm and membrane in most of the ATP6V1G3-positive RCC cases, but a subset of cases showed a predominance for expression in either the cytoplasm or the membrane (Figure 2A–L).