Y-27632 dihydrochloride is a selective ROCK inhibitor (Ki values are 0.14-0.22, 0.3, 25, 26 and > 250 μM for ROCK1 (p160 ROCK), ROCK2, PKA, PKC and MLCK respectively). Also inhibits PRK2 (IC50 = 600 nM). Increases survival rate of human embryonic stem (hES) cells and iPSC undergoing cryopreservation