The rate of Akt1 mutation in PCa was 9%; we hypothesize that the mutations cause the aberrant methylation and/or upregulation of Akt1. Akt1 is the target of the antitumour drug arsenic trioxide, which is currently used for patients with acute promyelocytic leukaemia [31]. The gene discussed is AKT1; the disease is posterior cortical atrophy.