PRNP and Behcet disease: First, to investigate the effects of food and DAs on ASCR biosynthesis, we examined changes in the expression levels of four ASCR biosynthetic genes (acox-1, maoc-1, dhs-28 and daf-22) in L4 wild-type N2 and DA-deficient daf-9(dh6) daf-12(rh61 rh411) worms under AL feeding and BD conditions.