ISG15 and neoplasm: Finally, Cluster 8 was equally conserved across healthy and tumor-associated neutrophils (Fig. 1A and B; Supplementary Fig. S1B) and was enriched for IFN markers: Isg15, Rsad2, Ifit3, Ifit1, and Slfn4 (Supplementary Table S3), a phenomenon previously reported in several scRNA-seq studies of neutrophils (29).