Recently, Manara et al. showed that anti-CD99 antibody treatment creates a virtuous cycle that delivers intrinsic cell death signals to EWS cells; promotes tumor cell phagocytosis by macrophages that, like EWS cells, express CD99 at high levels; and induces the reprogramming of M0 macrophages to M1-like macrophages, which are pro-inflammatory and typically associated with tumor regression. This evidence concerns the gene CD99 and neoplasm.