PDCD1 and neoplasm: Klrb1c encodes NK1.1 which is a transmembrane subunit of the co-inhibitory killer cell lectin-like receptor subfamily B. Previously, Klrb1c was identified as a gene associated with anti-tumor immunity when whole transcriptome profiling was performed using RNA-seq to dissect the molecular mechanism underlying resistance to anti-PD-1 immunotherapy in MC38 tumors26.