Of the remaining seven cases, serum analysis for autoantibodies led to the diagnosis of four further probable autoimmune psychosis cases (57.1%): anti-CASPR2 associated psychosis with ovarian teratoma (case #33, previously published by Herrmann15), anti-CASPR2 associated psychosis without confirmed tumor (#116), serum anti-zinc finger protein 4 (zic4) and anti-titin (#139), and anti-amphiphysin- (#98). This evidence concerns the gene ZIC4 and psychotic disorder.