Other AMPK‐independent pathways reported to mediate the antitumour effect of metformin in PCa included upregulation of REDD150 and reduction of cyclin D1 and pRb phosphorylation inducing cell cycle arrest40; in N‐cadherin expressing PC‐3 cells, metformin reduced TWIST1 thereby silencing N‐cadherin and decreasing p65 (subunit of NF‐kB) resulting in apoptosis.44 The gene discussed is RB1; the disease is posterior cortical atrophy.