ROCK1 and obesity due to melanocortin 4 receptor deficiency: It is noteworthy that different from adipose tissues where ROCK2 appears to the major isoform contributing to ROCK activity, ROCK1 is reportedly the major isoform in liver and mediating diet-induced obesity and insulin resistance through the ROCK1/AMPK signaling pathway (47, 48, 59, 125, 181) (Figure 1).