The pathway for IFNy upregulation runs like this -

The pathway for IFNy upregulation runs like this - Binding of CCL5 to CCR5 causes an increase in intracellular CA2+. Increased CA2+ elevates nuclear factor of activated T-cells (NFAT). NFAT in turn upregulates IFNy. Blocking CCR5 reverses this process. NFAT also elevates other proinflammatory cytokines. It's the elevation of CCR5 in response to cancer that upregulates IFNy and the tumor protectant PD-L1 and also increases activation of other inflammatory chemokines.