TGFB1 and precursor B-cell acute lymphoblastic leukemia: Another TGFβ family member deregulated within the B-ALL BM niche was Activin A. Our group recently described a significant increase in this molecule in the BM plasma of a large cohort of pediatric B-ALL patients, compared to HDs, and a higher Activin A production in ALL-MSCs, compared to HD-MSCs [63].