IDO1 and in situ carcinoma: When correlations between the expression of the proinflammatory and anti‐inflammatory cytokines and IDO and ARG were analysed, no associations were observed in PBMCs from the HC, CIS and MS groups, with the exception of a positive correlation between ARG1 and TGFB mRNA in cells from CIS patients (columns for PBMC ex vivo, Table 1).