LARP4 (La ribonucleoprotein 4) is an RNA-binding protein that plays crucial roles in mRNA metabolism and cellular regulation. LARP4 binds directly to poly(A) tails of mRNAs and interacts with cytoplasmic poly(A)-binding protein (PABP) to protect mRNAs from deadenylation and decay 1. The protein associates with ribosomes through its conserved region-2 (CR2) domain, which directly binds ribosome-associated RACK1, promoting translational efficiency of specific mRNA subsets 2. Beyond RNA metabolism, LARP4 regulates cell morphology and migration through mechanosensitive interactions with filamin A (FLNA). LARP4 binds to FLNA's immunoglobulin-like repeat 21 domain in a force-dependent manner, and this interaction competes with integrin β7 tails for FLNA binding 34. Functionally, LARP4 acts as a tumor suppressor in some contexts, with reduced expression observed in non-small cell lung cancer 5. However, in T cell immunity, LARP4 drives dysfunction by promoting hypertranslation of oxidative phosphorylation mRNAs, leading to mitochondrial imbalance and T cell exhaustion in tumor microenvironments 6. This dual functionality highlights LARP4's context-dependent roles in both RNA regulation and cellular mechanotransduction.