A concern for an increased risk of malignancy has been raised with other immunosuppressive therapies used for the treatment of psoriasis, such as anti–tumor necrosis factor (TNF) inhibitors, owing to the role of TNF in tumor growth inhibition.23 This is a review of the currently available information on the role of IL‐12 and IL‐23 in tumor growth and is written for clinicians who want to understand the potential risk of malignancy associated with blocking IL‐12 and/or IL‐23 in the treatment of psoriasis. The gene discussed is TNF; the disease is neoplasm.