Compared to WT mice, blood vitamin C was largely depleted in the HF diet-fed SMP30-KO mice when measured at the end of the study (Fig. 1a), suggesting that the WT, but not SMP30-KO mice, endogenously synthesize vitamin C. The body weight of HF-fed SMP30-KO mice was higher than that of WT mice (Fig. 1b). Here, RGN is linked to hydrops fetalis.