Monocrotaline (Crotaline) is a pyrrolizidine alkaloid and a toxic plant constituent that poisons livestock and humans through the ingestion of contaminated grains and other foods. The alkaloid causes pulmonary artery hypertension, right ventricular hypertrophy, and pathological changes in the pulmonary vasculature. Significant attenuation of the cardiopulmonary changes is noted after oral magnesium treatment.

Chromenone 1 is a potent potentiator of osteogenic bone morphogenetic protein (BMP). Chromenone 1 induces a pronounced, kinase-independent, negative TGFβ feedback that enhances nuclear BMP-Smad signaling outputs.

RepSox (ALK5 Inhibitor II) is a TGFβR-1/ALK5 inhibitor that selectively inhibits the binding of ATP to ALK5 and the autophosphorylation of ALK5 (IC50=23/4 nM). RepSox induces adipogenesis in MEFs cells.

Galunisertib (LY2157299) is a TGF-β receptor type I (TGF-βRI) inhibitor (IC50=56 nM) that is selective. Galunisertib has antitumor activity and can be used in combination with PD-1 inhibitors.

A 83-01 (ALK5 Inhibitor IV) is an inhibitor of the TGF-β type I receptors ALK5, ALK4, and ALK7 (IC50=12/45/7.5 nM). A 83-01 promotes the reprogramming of mouse fibroblasts into iPSCs. A 83-01 can be used in organoid cultures.