library_construction_protocol: Subcutaneous B16 tumours were implanted on the back mice. On day 19 after tumours were injected, tumors were collected, weighed and chpped before chemical and mechanical digestions with Tumour Dissociation Kit II (Myltenyi) and gentleMACS DIssociator (Myltenyi) using the m-TDK-1 program. Immune cells were isolated by density centrifugation with Lympholyte (Cederlane Labs) followed by positive selection for CD8a+ cells (Myltenyi). CD8+ cells were pooled into samples from 5-11 tumours, depending on cell counte recovered. Live cells were sorted into Tim3+ (10,000 cells) and Slamf6+ (1,000 cells) populations with two pooled samples per treatment condition. RNA was harvested using Rneasy micro kit (Qiagen). PolyA RNA was isolated using the NEBNext Poly(A) mRNA Magnetic Isolation Module First-strand Illumina-barcoded ibraries were constructed using the NEBNext Ultra II Directional RNA Kit. During the library construction Ilumina R2 primer sequence, P7 sequences and a sample index were added.