IFNA1 and ischemic colitis: To our knowledge, the molecular mechanisms underlying PEG-IFN-α-associated ischemic colitis has not been established, while ischemic colitis has not been reported with other Peg proteins (e.g., pegvisomant, pegfilgrastim or pegademase), suggesting that the inert, polyethylene glycol moiety of PEG-IFN-α is unlikely to be the causative agent.