STAT3 and malignant colon neoplasm: Evidence in the literature demonstrated that STAT3 signalling regulates PD-1 expression on the surface of T cells38 and PD-L1 expression on the surface of colon cancer cells39, therefore, we hypothesised that STAT3 signalling may regulate PD-1 expression and perhaps other ICs on the surface of OAC cells and assessed if STAT3 inhibition might affect basal expression of tumour-expressed ICs or FLOT-induced upregulation of ICs (Figure S2).