FRMD1 (FERM domain containing 1) is a protein containing a FERM (Four-point-one, Ezrin, Radixin, Moesin) domain that localizes to the plasma membrane and cell-cell junctions 1. The protein exhibits protein binding activity and functions in positive regulation of Hippo signaling 2, a pathway critical for controlling cell growth and tumor suppression. FRMD1 is part of the FAT-Hippo signaling cascade, which includes structural proteins that suppress tumor growth through Hippo pathway activation 2. The gene shows tissue-specific expression patterns 1 and has been identified as a missing protein, historically lacking experimental protein-level evidence despite being protein-coding. Clinically, FRMD1 exhibits disease relevance through multiple mechanisms. Haplotype-dependent allele-specific methylation at FRMD1 is associated with immune phenotypes and shows cell-type-restricted epigenetic regulation 3. Additionally, FRMD1 dysregulation has been implicated in Adult T-cell Leukemia/Lymphoma (ATLL) pathogenesis, appearing as a specific dysregulated gene in ATLL development 4. As part of the FAT-Hippo signaling network, FRMD1 mutations warrant comprehensive investigation in cancer genomics for diagnostic, prognostic, and therapeutic applications in personalized medicine 2.