TGFB1 and carcinoma: The goblet cell expansion and conjunctival epithelial hyperplasia observed in Tgfbr2cKO mice does not have the morphological features indicative of a malignant lesion, and maintains an intact basement membrane, indicating that the loss of TGF-β signaling in the ocular surface epithelium is sufficient to promote epithelial hyperplasia but is insufficient for progression to carcinoma.