The interaction of cytokines in psoriasis can be elucidated by positing a linear correlation among inducers such as IL-23 or IL-12, the synthesis of interferon-gamma and TNF by T-cells, and the ensuing activation of interferon-responsive genes through signal transducer and activator of transcription (STAT) 1 (Wang et al. 2021). The gene discussed is TNF; the disease is psoriasis.