ACVRL1 and neoplasm: In support of this hypothesis, ALK1-co-expressed genes were highly enriched in IL2/STAT5 and IL6/JAK/STAT3 pathways; the former has been implicated in the proliferation and development of peripheral T cells and regulatory T cells [33, 34], whereas the latter is a strong and recognized tumor immunosuppressive signaling cascade [35, 36].