Reply to Liu et al.: ALK5-mediated tumor suppressor signaling through SMAD2 and SMAD3 in the uterus

Our recent publications in PNAS (1, 2) describe the phenotypic effects of loss of activin-like kinase 5; transforming growth factor β receptor 1 (ALK5;TGFBR1) or Smad2 and Smad3 in the mouse uterus and are accompanied by a commentary by Li (3). Our conclusions are that this pathway acts as a tumor suppressor pathway, findings that are also supported by a recent paper (4). We appreciate the letter to the editor by Liu et al. (5); however, their analysis is performed utilizing data from uterine cancer samples from The Cancer Genome Atlas (TCGA) and should be cautiously interpreted for the following reasons: [↵][1]2To whom correspondence should be addressed. Email: mmatzuk{at}bcm.edu. [1]: #xref-corresp-1-1