TGFB1 and breast cancer: As expected, nuclear PTPN18 inhibited the expression of TGFβ1-regulated genes in breast cancer cells, and the suppressive role of nuclear PTPN18 in cell migration was validated by Transwell assays (Fig. 5H, I; Fig. S6H, I) and wound healing assays (Fig. 5J, K; Fig. S6J, K) in multiple breast cancer cell lines.