Recent human studies have pointed out that specific polymorphisms of c-fos gene may be either negatively or positively associated to schizophrenia, since decreased Fos protein blood levels may be found in schizophrenia patients (Boyajyan et al., 2015), thus reinforcing the possibility of an implication of this IEG in schizophrenia pathophysiology and, possibly, in its treatment. The gene discussed is FOS; the disease is schizophrenia.