PCDH7 (protocadherin 7) is a non-clustered protocadherin belonging to the δ1 subgroup, primarily expressed in the nervous system with region-specific patterns in cortical and hippocampal areas 1. As a cell adhesion molecule, PCDH7 mediates homophilic/heterophilic cell-cell adhesion and engages in distinct cell signaling partnerships 1. In cancer biology, PCDH7 promotes assembly of gap junctions between carcinoma cells and astrocytes through connexin 43, facilitating transfer of the second messenger cGAMP and subsequent activation of pro-inflammatory pathways (STING, STAT1, NF-κB) that support brain metastatic growth and chemoresistance 2. Clinically, PCDH7 has emerged as a novel target antigen in membranous nephropathy (MN), a common cause of adult nephrotic syndrome 3. PCDH7-associated MN occurs when autoimmune responses generate IgG antibodies against PCDH7, leading to subepithelial immune complex deposition along the glomerular basement membrane; this distinct disease entity accounts for approximately 5.7% of PLA2R-negative MN cases and shows minimal complement deposition 34. Genome-wide association studies have also identified PCDH7 variants linked to epilepsy susceptibility 5, suggesting roles in synaptic function. Gap junction modulators offer potential therapeutic approaches for PCDH7-associated brain metastasis.