PRKAA1 and cystic kidney disease: At the mRNA level, although no significant change was observed in the expression of PRKKA2 (encoding AMPKα2), we found slightly increased expression of PRKAA1 (1.5×, encoding AMPKα1) in human PKD1 renal cysts, consistent with the isoform shift in the catabolic subunit of AMPK from AMPKα2 to AMPKα1 in renal fibrosis [77,78,79].