The ACVR1 protein can bind to Activin A, BMP2, BMP5, BMP6, BMP7, or BMP9 but not the other BMPs, and trigger SMAD1/5/8 signaling.[18] Our data indicate that BMP‐ACVR1 signaling is not only required for the anti‐tumor efficacy of PRC2 inhibitor, but also repressed by PRC2 and upregulated upon PRC2 inhibition (Figure 1H). Here, BMP6 is linked to neoplasm.