TGFB1 and colorectal carcinoma: Current studies of anti–PD-1 agents suggest that their clinical effect is generally unencouraging in patients with pMMR or MSS CRC.9,10 The observed modest antitumor activity of dual inhibition in the present study suggests that simultaneous inhibition of TGF-β and PD-L1 pathways with bintrafusp alfa could not overcome PD-L1 resistance across this patient population.