We found that these hallmarks with higher IDO1 level in five female cancers were mainly involved in immune‐related hallmarks, including interferon gamma response, allograft rejection and interferon alpha response, TNFa signalling via NF‐kB, IL6‐Jak‐Stat3 signalling, Kras signalling up, apoptosis, reactive oxygen species pathway, inflammatory response, complement and IL2‐Stat5 signalling (Figure 4A). This evidence concerns the gene IL2 and cancer.