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HRH1 is the gene name for Histamine Receptor H1. Learn what a specific result could mean and what to ask about it.

HRH2 is the gene name for Histamine Receptor H2. Learn what a specific result could mean and what to ask about it.

IL21 encodes a cytokine involved in regulating lymphocytes, including B-cell responses. It sits within an immune network that connects T-cell help, antibody responses and inflammatory activity.

IL23R encodes part of the receptor that receives IL-23 signals. This connects the gene to the maintenance of Th17-related immune responses, which differ from the Th2 patterns discussed in allergy.

IL6 encodes interleukin-6, a cytokine involved in immune responses and acute-phase signaling. It can appear in discussions of infection, chronic inflammation and metabolic health, with effects that depend on the context.

KIT encodes a receptor tyrosine kinase that responds to stem cell factor. It participates in blood-cell development and mast-cell biology, making the exact variant and testing context especially important.

Makes an enzyme that helps produce a form of folate used in the processing of homocysteine. Common variants are different from rare variants that cause severe MTHFR deficiency.

Makes an enzyme involved in producing phosphatidylcholine, a component of cell membranes. Genetic findings alone do not establish a choline deficiency.

SOD3 works outside cells as part of the body’s antioxidant defenses.

TNF encodes tumor necrosis factor, an immune-signaling protein involved in inflammation, host defense and regulation of cell survival. Its name should not be read as proof that a TNF result indicates cancer.

VDR encodes the vitamin D receptor, which helps regulate gene activity in response to active vitamin D. A receptor variant does not by itself mean receptors are absent or that the blood vitamin D level is low.

Encodes the reduced folate carrier, a protein involved in transporting folates into cells.