GADD45B and diabetic kidney disease: The ERK pathway has been shown to have a key role in the development of DKD (Zhang et al., 2014; Chang et al., 2017), and our data indeed uncovered the activation of ERK both in vivo and in vitro, but altered GADD45B expression did not affect the activity of ERK in HK-2 cells, indicating that ERK is not a crucial signaling molecule in GADD45B-regulated renal tubular EMT and apoptosis.