Family with sequence similarity 138 member B (FAM138B)

Family with sequence similarity 138 member B (FAM138B) encodes a small, likely retina-specific peptide, identified as “F379.” The canonical transcript is notable for the presence of repetitive elements (Alu and MIR repeats) and lacks detectable homology to characterized protein families[2][4]. FAM138B is dispersed polymorphically across subtelomeric regions of several human chromosomes, but its transcript is most abundant in retinal tissues[2]. The prevailing clinical interest is not in the peptide itself, but rather in linc-FAM138B, a long non-coding RNA variant derived from this locus. This lncRNA acts through sequestration of miR-765 and has been implicated in the regulation of hepatocellular carcinoma progression and prognosis, as well as lung adenocarcinoma, suggesting its use as a biomarker and a mechanistic player in cancer cell communication and invasion[1]. There are no known drugs targeting FAM138B, and it is not classified as a receptor, enzyme, transporter, or any of the classical therapeutic target classes. Its main clinical relevance is as a noncoding RNA biomarker rather than a druggable protein product[1][2][4].

Other names

F379bA395L14.6F379 retina-specific proteinChromosome 2 F379 retina specific proteinFAM138B

None reported (not established as a druggable entity; mechanism relevant to linc-FAM138B’s action as a miRNA sponge on miR-765)