TGFB1 and neoplasm: Galunisertib is a small molecule inhibitor that binds the intracellular serine-threonine kinase domain of TGFβR1 and thereby prevents phosphorylation SMAD2/3 signaling and nuclear translocation which disrupts TGFβ1-mediated signaling Moreover, using multicolor flow cytometry we identified tumor-associated macrophages (TAMs), B cell populations and Tregs to be the main cell types associated with the suppressive factor profile found in ascites of advanced EOC patients.