SB-431542 is a drug candidate developed by GlaxoSmithKline (GSK) as an inhibitor of the activin receptor-like kinase (ALK) receptors, ALK5, ALK4 and ALK7. However, it is not an inhibitor of anaplastic lymphoma kinase (which are commonly known as ALK inhibitors). SB-431542 is a drug candidate developed by GlaxoSmithKline (GSK) as an inhibitor of the activin receptor-like kinase (ALK) receptors, ALK5, ALK4 and ALK7. However, it is not an inhibitor of anaplastic lymphoma kinase (which are commonly known as ALK inhibitors). While SB-431542 has not proved directly useful for any clinical application, it is used for several applications in molecular biology. It suppresses the TGF-beta-induced proliferation of osteosarcoma cells in humans. Treatment with SB431542 is a robust, clinically applicable, and efficient system for generating mesenchymal stem/stromal cells (MSCs) from human iPSCs. SB431542 can also be used in combination with LDN193189, CHIR99021 and DAPT to transform astrocytes into neurons.