TMEM87B (transmembrane protein 87B) is a Golgi-resident membrane protein that functions in retrograde transport from endosomes to the trans-Golgi network (TGN) 1. The protein belongs to the GOLD domain seven-transmembrane helix (GOST) protein family, which includes eight structurally related proteins that may serve common roles in trafficking membrane-associated cargo 2. TMEM87B can partially restore both endosome-to-TGN retrograde transport and anterograde transport when overexpressed in cells with defective GARP complex function, indicating its involvement in maintaining efficient protein trafficking pathways 1. The protein appears to play important roles in development, as TMEM87B knockdown in zebrafish results in cardiac hypoplasia, and its deficiency has been implicated in congenital heart defects associated with 2q13 deletion syndrome 34. In pathological contexts, TMEM87B is upregulated in glioma and promotes tumor progression while decreasing sensitivity to temozolomide chemotherapy 5. Additionally, differential expression of TMEM87B has been observed in cluster headache patients, suggesting potential involvement in neurological conditions 6. However, the precise molecular mechanisms underlying these diverse functions require further investigation.