COG5 and Obesity: Cross-comparison analyses revealed ten additional genes, CDH4, NR3C2, ACTG1, COG5, CAT, HDAC4, FTO, DOK7, OCLN, and ATXN1, that were differentially methylated by sleep timing and have also been implicated in obesity-related pathways (Table A2 in Appendix A provides full abbreviations and functions), suggesting an epigenetic interface connecting circadian regulation and metabolic health.