Explore the
health encyclopedia.

GSTP1 helps your body use glutathione to process some compounds.

GSTT1 helps your body use glutathione to process some compounds.

HDC is the gene name for Histidine Decarboxylase. Learn what a specific result could mean and what to ask about it.

HFE helps regulate iron absorption through signaling that influences hepcidin. The commonly discussed C282Y and H63D variants correspond to rs1800562 and rs1799945. Their implications depend on the combination present and clinical findings.

HLA-DQA1 contributes to an HLA-DQ protein that presents antigen fragments to CD4 T cells. HLA-DQ function depends on pairing with an HLA-DQB chain, so an isolated marker is not a complete HLA type.

HLA-DQA2 is part of the HLA class II region involved in immune recognition. It should not be treated as interchangeable with HLA-DQA1 or as a measurement of how well the immune system fights infections.

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.