CARS also knonw as CYSRS is a class I aminoacyl‑tRNA synthetase that ligates cysteine to its cognate tRNA to ensure translational fidelity in the cytosol. By controlling the supply of charged tRNA. CARS supports global protein synthesis and couples amino acid availability to proteostasis pathways, including stress responses that modulate translation. Perturbation of aminoacyl‑tRNA synthetase activity can alter ribosome dynamics and trigger integrated stress signaling, with downstream effects on cell growth, metabolism, and redox-sensitive processes that depend on cysteine utilization. Dysregulation of tRNA charging and translation quality control is relevant to research on neurodevelopmental and neuromuscular phenotypes, proliferative disorders, and cellular stress adaptation.