PIK3R5 and melanoma: While under basal conditions the number of cDCs was identical between WT and p84 or p101‐deficient mice (Figure S2A,B, Supporting Information), when we isolated cDCs from mice injected with Flt3L‐expressing B16 melanoma, a small but significant reduction in the percentage of type 1 DCs was observed in mice deficient for p101 or p84 and a slight significant increase in type 2 DCs was observed in mice deficient for p101 (Figure S3, Supporting Information).