C1QA and sarcopenia: The application of LASSO (Least Absolute Shrinkage and Selection Operator) and SVM-RFE (Support Vector Machine–Recursive Feature Elimination) methods allowed for the identification of specific gene sets with increased expression (TPPP3, C1QA, LGR5, MYH8, CDKN1A) and decreased expression (SLC38A1, SERPINA5, HOXB2), providing a molecular basis for understanding the pathogenetic mechanisms of sarcopenia [235].