For the SARC—Calf tool, the authors found significant differences in the mean scores of variables such as employment status (p = 0.029), economic class (p = 0.004), smoking (p = 0.009), disease status (p < 0.001), opportunistic infections (p = 0.015), CD4 T-cell count (p = 0.002), sarcopenia construct (p = 0.001), and all its components, including HGS (p = 0.001), ASMI (p = 0.009), and GS (p < 0.001) (Table 1). The gene discussed is CD4; the disease is sarcopenia.