GJB7 encodes connexin-25, a gap junction protein that forms intercellular channels for cell-to-cell communication. As a connexin, GJB7 assembles with five other connexin molecules to create hemichannels (connexons) that dock with homologous proteins in adjacent cells, forming functional gap junctions with approximately 16 Ångstrom pores 1. These channels permit direct diffusion of small water-soluble molecules up to approximately 1000 daltons between adjacent cells 1. GJB7 is functionally expressed and capable of mediating dye transfer in transfected cells, confirming its role in intercellular communication 1. In disease contexts, GJB7 frameshift mutations occur in colorectal and gastric cancers with high microsatellite instability (MSI-H), appearing in approximately 1% of MSI-H colorectal cancers 2. These mutations may contribute to tumorigenesis by altering gap junction function and cellular communication integrity 2. Additionally, GJB7 expression is elevated in acute leukemia cells compared to normal hematopoietic stem cells, and Cx25-dependent gap junctions mediate homotypic leukemia cell communication that influences chemosensitivity 3. Reducing Cx25 expression sensitizes leukemia cells to chemotherapy, suggesting therapeutic potential 3. Notably, nonsyndromic deafness does not arise from GJB7 mutations in sub-Saharan African populations 4.