PPM1L, or PP2CE, belongs to the PP2C group of serine/threonine phosphatases, which are distinguished from other phosphatases by their structure, absolute requirement for Mg(2+) or Mn(2+), and insensitivity to okadaic acid. PP2Cs regulate stress-activated protein kinase (SAPK; see MIM 601158) signaling cascades that respond to extracellular stimuli (Jin et al., 2004 [PubMed 15560375]).[supplied by OMIM, Apr 2008]