Several studies have indicated that the dysregulated PI3K/AKT, extracellular signal-regulated kinase (ERK)/MAPK and AMPK signalling pathways are associated with PCa progression, and that HFD can activate AKT and ERK signalling.27 To explore the expression of protein kinase pathways in HFD-induced PCa tumour growth, we investigated the expression of AKT, P-AKT, ERK, P-ERK, AMPK, P-AMPK and Ki67 in xenograft tumours by immunohistochemistry and/or western blotting (Figures 1e–g; Supplementary Figures S2 and S3). This evidence concerns the gene AKT1 and posterior cortical atrophy.