SLCO1B1 encodes OATP1B1, an organic anion transporting polypeptide expressed on the basolateral membrane of hepatocytes. It is classified as a hepatic solute carrier involved in uptake of bile acids, bilirubin conjugates, certain sterols, and multiple commonly used medications. The two variants tested here—often reported as rs4149056 and rs2306283 (c.388A>G)—are among the most frequent SLCO1B1 polymorphisms studied in clinical research. These variants were identified through population genetic and pharmacogenomic studies that linked differences in SLCO1B1 sequence to altered transporter activity. Laboratory and clinical association work has shown that these alleles can change hepatic uptake efficiency, which in turn affects circulating levels of OATP1B1 substrates and can help explain inter-individual variability in drug exposure and some lipid biomarkers.

Results indicating genotypes associated with reduced OATP1B1 activity (for example, alleles linked to lower function) suggest less hepatic uptake of OATP1B1 substrates; this pattern is associated with higher circulating levels of those substances and altered lipid-related signals. Genotypes associated with normal or increased transporter activity suggest more efficient hepatic uptake and may be linked to lower circulating substrate levels. Genetic findings should be interpreted alongside medication lists, advanced lipid measures, and other Cardio Zoomer markers to build a complete picture of causes and patterns.

SLCO1B1 genotyping in Cardio Zoomer adds pharmacogenomic and hepatic-transport context to advanced lipid and metabolic markers. It helps explain why two people with similar labs or medications may show different blood levels or lipid patterns, supporting more precise interpretation of test results and individualized clinical planning.