Fc Fragment of IgE Receptor Ig (FCER1G), also known as the high-affinity IgE receptor gamma subunit gene, plays a pivotal role in allergic inflammatory signaling, closely associated with allergic reactions. It is an innate immunity gene involved in many immune-related pathways encompassing multiple cell types [3].

FCER1G has been studied in various disease contexts. In cardioembolic stroke (CE), it could serve as a novel potential blood biomarker, helping distinguish CE from non-cardioembolic stroke. The development of a nomogram using FCER1G and other CE-associated risk factors showed high precision in risk delineation [1].

In rheumatoid arthritis (RA), patients have lower levels of FCER1G gene methylation compared to controls, suggesting it may be a new potential epigenetic marker of RA independent of disease activity [2].

In pan-cancer studies, FCER1G can act as a prognostic marker, with its expression affecting patients' prognosis and correlating with immune cells infiltration. For example, in kidney renal clear cell carcinoma, high expression of FCER1G is related to tumor-associated macrophage infiltration and T-cell suppression, contributing to an unfavorable prognosis [3,4].

In multiple myeloma, the expression level of FCER1G negatively correlates with myeloma progression, and high FCER1G expression may be a favorable biomarker [5].

In female patients with Vogt-Koyanagi-Harada disease, downregulation of FCER1G due to DNA hypermethylation is responsible for resistance to the combination of cyclosporin A and corticosteroids, and chlorambucil reverses this resistance by inducing FCER1G expression via DNA demethylation [6].

In conclusion, FCER1G is crucial in immune-related biological processes and shows potential as a biomarker and a target in various diseases such as stroke, autoimmune diseases, and cancers. Studies on FCER1G contribute to a better understanding of disease mechanisms and may offer new strategies for diagnosis and treatment.