Like cluster 17 cells, cluster 9 cells also expressed GZMA, GZMB, GZMH, GNLY, and PRF1. CD8+ T cells in ICC/IDC-enriched prostate had a higher expression of PDCD1 and LAG3 and decreased IFNG, thereby suggesting that cluster 9 CD8+ T cells in benign-enriched regions were more cytotoxic while cluster 9 CD8+ T cells in ICC/IDC-enriched regions were more dysfunctional (Fig. 6l, DEG analysis for cluster 9 in Source Data). The gene discussed is PRF1; the disease is intrahepatic cholangiocarcinoma.