There was no significant difference in tumor growth between the two groups (online supplemental figure S7C), while a significant increase in IL-6 was found in the TCM of B16-F1-IL-6 group compared with B16-F1-EV (online supplemental figure S7D), suggesting that IL-6 has no direct protumorigenic role in the primary tumor microenvironment. The gene discussed is IL6; the disease is neoplasm.