Inhibition was dependent upon Sema4D binding to Plexin-B1 since this effect was lost in MC3T3 cells where Plexin-B1 was silenced with short hairpin (sh)RNA (Fig 1C, Plexin-B1 shRNA, lower panel, second row; knockdown confirmed by immunoblot, top panel), or where cells were incubated with an anti-Sema4D blocking antibody (Fig 1C, lower panel, last row), an antibody that our group and others have shown to block interaction with Plexin-B1 and inhibit Sema4D functioning in angiogenesis, tumor growth, and immunomodulation [28–30]. This evidence concerns the gene SEMA4D and neoplasm.