Among the choroidal pathways in the overall category at myopia onset are those related to neurotransmitters (e.g., GABA, serotonin, acetylcholine, GABA), cones, rhodopsin, visual transduction, ion channels, inflammation, etc. The pathway differences, especially for retina, further support the notion of substantial differences in the mechanisms of myopia onset and progression. The gene discussed is RHO; the disease is myopia.