Pooled transductants sorted for high transgene expression were stained with anti-hPSMA-APC Ab, demonstrating ~ threefold higher median cell surface expression of hPSMA(NΔ9) compared with hPSMA (Fig. 1b), although still lower than the endogenous level of hPSMA on the LNCaP human prostate cancer line (Fig. 1c). Here, APC is linked to prostate carcinoma.