Although concerns have been raised regarding the potential toxicity of ALK5 inhibitors, several in vivo studies have reported effective tumor suppression or antifibrotic outcomes without significant side effects (Jing et al., 2025; Sounbuli et al., 2022; Tschernia and Gulley, 2022), Specifically, Galunisertib has shown a favorable safety profile, with no significant toxicity observed in preclinical models, for instance, in a murine model of breast cancer (Yingling et al., 2017), as well as in bone marrow fibrosis (Yue et al., 2015) and liver fibrosis models (Hammad et al., 2018). The gene discussed is TGFBR1; the disease is breast cancer.