SLPI and sarcopenia: In the sarcopenia dataset, the random forest model identified 10 genes, including secretory leukocyte peptidase inhibitor (SLPI), insulin receptor substrate 1 (IRS1), nipsnap homologue 3B (NIPSNAP3B), C1QB, cyclin dependent kinase inhibitor 2B (CDKN2B), nuclear receptor subfamily 1 group D member 1 (NR1D1), CLIC5, cytochrome P450 family 1 subfamily B member 1 (CYP1B1), SLC38A1, and complement C1q A chain (C1QA) (Figure 4C,D).