TGFB1 and neoplasm: Given that the challenges associated with TGFβ blockade are likely due to the loss of a TGFβ‐mediated suppression of tumor cell proliferation, which is mediated via canonical TGFβ signaling in tumor cells (Bardeesy et al, 2006; Ijichi et al, 2006), we hypothesized that patients who harbor a loss‐of‐function mutation in TGFBR2 could benefit from TGFβR2 inhibition.