PMP22 and neoplasm: Thirty days after implantation, we observed that the sizes of xenograft tumors in mice injected with SGC7901-PMP22 cells were larger than the tumors in mice injected with SGC7901-Ctrl cells after treatment of etoposide, while the difference between the two groups treated with PBS was not very prominent (Fig. 6A-B) Consistent with this result, knockdown of PMP22 reduced tumor growth, and this inhibition was more obvious after etoposide treatment (Fig. 7A-B).