Therefore, the development of KAs is suggestive of an on-target effect of GC1008 where neutralization of TGFβ by GC1008 appears to mimic the loss of TGFβ signaling found in patients with Ferguson-Smith disease and is consistent with a clinical TGFβ neutralizing effect of GC1008. This evidence concerns the gene TGFB1 and multiple self-healing squamous epithelioma.