A recent study reported that obesity induces the loss of Stella, a maternal factor required for the protection of 5mC DNA methylation from TET3-mediated demethylation by binding to maternal chromatin containing H3K9me2 [Nakamura et al., 2012], and causes rapid conversion of 5mC to 5hmC in the maternal pronuclei of zygotes, thereby contributing to reproductive disorders, though the molecular mechanism of Stella regulation in obese mice has not been elucidated [Han et al., 2018]. The gene discussed is DPPA3; the disease is obesity due to melanocortin 4 receptor deficiency.