FST and neoplasm: Expression of INHA, coding for the α-subunit of Inhibin, and FST, coding for the secreted activin antagonist follistatin, was also very low (Supplementary Fig. 12b), suggesting that the increased levels of INHBA mainly give rise to homodimeric Activin A. To consolidate these data, we interrogated tumor AOIs for INHBA and INHBB expression (as part of the CTA panel).