It has been shown before that moDCs derived from ascites of patients with ovarian cancer were differentiated from monocytes.32 These tumor-derived moDCs were capable of cross-presenting exogenous antigens to CD8+ T cells, and they also provided co-stimulatory signals like CD86.32 Indeed, we find “monocyte activation” and “cDC2” gene sets correlated with CD8+ T cells only in patients with melanoma exhibiting a partial or complete response to αPD1 treatment, compared with patients who show progressive disease. The gene discussed is CD8A; the disease is melanoma.