Schizophrenia patients with and without concomitant MetS treated with olanzapine or clozapine had significantly higher plasma IL-6, IL-10 and TNF-α levels compared to the normal controls, but markedly lower plasma silencing information regulator 2-related enzyme 1 (SIRT1) levels and higher plasma IL-6 levels were observed in patients with MetS compared to patients without MetS [25]. Here, TNF is linked to schizophrenia.