CA9 and renal cell carcinoma: To ascertain the ability of these antibodies to mediate immune cell killing of CAIX-expressing RCC cells, we chose to analyze high affinity scFv-Fc antibodies that either inhibited the CA activity of CAIX, but did not internalize (G37 and G39), or showed minimal to modest inhibition of CA activity and induced internalization of CAIX (G10, G36, and G119) [23].