PMP22 and neuropathy: Regarding the severity of phenotypes, other CMT1A models carrying more hPMP22 copies, such as C22 mice (7 copies) (22) and TgN248 mice (16 copies) (38), generally have more severe neuropathy phenotypes than mild models including PMP22-C3 mice (3–4 copies), C61 mice (4 copies) (31), and JP18/JY13 mice (2 copies) (39), which may be more relevant to severely affected patients in the CMT1A.