SB 431542 is a potent and selective inhibitor of the transforming growth factor- beta (TGF- beta) type I receptor/ALK5, with an IC50 value of 94 nM, and also inhibits the related ALK4 and ALK7. SB 431542 inhibits TGF- beta-induced epithelial to mesenchymal transition (EMT) migration, invasion and VEGF secretion in several human cancer cell lines, and suppresses TGF- beta-induced proliferation of human osteosarcoma cells. SB 431542 can replace SOX2 in reprogramming of fibroblasts into induced pluripotent stem cells (iPSCs) and can also be used in a protocol to generate brain organoids from human iPSCs.
