PRKAA1 and type 2 diabetes mellitus: To investigate the possible association of the genetic variants in six genes (PRKAA1, STK11, PCK1, PPARGC1A, HNF1A and CAPN10), encoding the key molecules mediating the metformin pharmacodynamic effect, with the response to metformin treatment Tkáč and colleagues performed a study on a small cohort of patients with T2D.