We also performed an analysis using another single-cell data cohort containing 32 melanoma patients treated with anti-PD1 (Fig. S21A-D) and found that in S100A9 + myeloid cell (Mye_C6_S100A9), the proportion of cells from responsive patients (87.25%) was much lower than that of cells from non-responsive patients (12.75%) (Fig. S21E). Here, PDCD1 is linked to melanoma.