This randomized, double-blind, sham-controlled study tested whether CACNA1C rs7304986 genotype modifies sleep EEG responses to 5G RF-EMF exposure. The authors report a genotype-by-exposure interaction, with 3.6 GHz exposure in T/C carriers associated with a faster NREM sleep spindle center frequency versus sham. The abstract also notes longer sleep latency in T/C compared with T/T carriers, and concludes that genetically susceptible groups may show differential physiological responses to 5G RF-EMF.