PLP1 and Pelizeaus-Merzbacher spectrum disorder: While the disease is thought to be mediated through mutant PLP-induced endoplasmic reticulum (ER) stress (Garbern, 2007), complete appreciation of the cellular and molecular pathology in PMD remains elusive, in part due to complexities in accessing or appropriately modeling the disease-affected oligodendrocyte lineage during critical developmental windows (Bradl et al., 1999, Cerghet et al., 2001, Duncan et al., 2011, Gow et al., 1998, Knapp et al., 1986, Knapp et al., 1987, Southwood et al., 2002, Williams and Gard, 1997).