Extracellular signal‐regulated kinases (ERKs) and Nuclear factor‐κB (NF‐κB) mediated downstream proteins, such as myeloid leukemia cell differentiation protein (MCL‐1), cellular FLICE‐inhibitory protein (C‐FLIP), X‐linked inhibitor of apoptosis protein (XIAP), Cyclin‐D1, matrix metallopeptidase 9 (MMP‐9), vascular endothelial growth factor‐A (VEGF‐A) and indoleamine 2,3‐dioxygenase (IDO) which involved in proliferation, survival, angiogenesis, invasion and anti‐tumor immunity were all decreased by quetiapine. The gene discussed is IDO1; the disease is neoplasm.