ATF6 and achromatopsia: It has been proven that ATF6 can be activated in two separate pathways: the protein toxicity activation pathway and the lipotoxic activation pathway, including specific sphingolipids, dihydrosphingosine, and dihydroceramide.353 It offers a unique way to treat ACHM with the ATF6 mutation through upregulating dihydroceramide by fenretinide, which facilitates ATF6 only in its normal function but not ER stress.