CLOCK and homocystinuria: We discuss a paradigm shift mechanistic pathway that causes the circadian clock-related diseases through the activation of the superior cervical ganglion (SCG) and the excitatory neurotransmitter receptor NMDA-R1 by disrupted epigenetic folate 1-carbon metabolism (FOCM) and increased homocysteine (Hcy, i.e., homocystinuria, HHcy) [11,12,13,14].