GNGT2 (G protein subunit gamma transducin 2) encodes a cone-specific gamma subunit of the heterotrimeric G-protein transducin, playing a critical role in phototransduction. 1 The protein is specifically localized in cone photoreceptors and shares 85% sequence identity with bovine cone G-protein gamma and 63% with rod G-protein gamma 1. 1 GNGT2 functions as part of the G-protein signaling complex required for GTPase activity and coupling of visual pigments to phosphodiesterase in cone visual perception. 1 Beyond vision, GNGT2 has emerging roles in neuroinflammation and immune regulation. In Alzheimer's disease, GNGT2 deletion influences amyloid-β and tau pathologies, with loss of Abi3-Gngt2 inducing pro-inflammatory microglial signatures and differential effects on neuropathological hallmarks. 2 In asthma, GNGT2 acts as an adapter molecule inhibiting autophagy in CD11b+ dendritic cells, promoting Th17-mediated airway neutrophilic inflammation in T2-low asthma models via GPCR signaling pathways. 3 GNGT2 also serves as a potential diagnostic biomarker in spinal cord injury, associated with macrophage-microglia cell activation. 4 Clinically, GNGT2 represents a promising therapeutic target for inherited retinal degenerations, with its promoter enabling sustained photoreceptor-specific gene expression even at mid-to-late disease stages. 5 The GNGT2-tagged fluorescent reporter line provides tools for investigating human cone photoreceptor development. 6