SLC24A4 encodes a sodium/potassium/calcium antiporter that exchanges one Ca²⁺ and one K⁺ for four Na⁺ across the plasma membrane, regulating intracellular calcium homeostasis. In olfactory sensory neurons, the transporter terminates the rapid response to odor stimulation and facilitates proper adaptation, thereby shaping how odor information is encoded and perceived. During tooth development, SLC24A4 is critical for enamel maturation; mutations cause inherited hypomaturation amelogenesis imperfecta, with affected individuals showing yellow-brown discolored, thin, and brittle enamel 12. SLC24A4 variants are also associated with normal pigmentation variation, including eye and hair color; specific alleles correlate with brown eye color in individuals with the rs12913832:GG genotype 34. At the population level, genetic variants in and near SLC24A4 associate with late-onset Alzheimer disease risk, though with small effect sizes 5. Recent evidence suggests that loss-of-function polymorphisms in SLC24A4 may impair calcium extrusion capacity and potentially contribute to age-related cognitive dysfunction 6, and altered methylation patterns in this gene appear in both brain and blood cells of individuals with Alzheimer disease 7. In colon adenocarcinoma, SLC24A4 expression influences tumor progression and has been identified as a potential tumor suppressor gene 8.