The following underlying mechanisms of OPMD have been speculated: (1) the mutated protein forms intranuclear aggregates, leading to toxicity; (2) the intranuclear aggregates sequester various transcription factors, molecular chaperones, RNA binding proteins, and RNAs necessary for cell maintenance; (3) reduction in the levels of wild-type PABPN1 by half suppresses its native function; or (4) the abnormal PABPN1 protein suppresses the function of wild-type protein [51]. Here, PABPN1 is linked to oculopharyngeal muscular dystrophy.