PDCD1 and neoplasm: We discovered higher expression of genes related to B cell recruitment in the ICI OT-R tumor, such as the ligand/receptor pair CXCL13 and CXCR5. Anti-PD1 antibody treatment of human immune cells upregulated CXCL13 while MAPKi inhibited CXCL13 production, suggesting that differential regulation of CXCL13 by these two treatments may dictate treatment outcomes.