Figure 4C depicts the expression patterns of the four SLC genes in high- and low-risk groups. Kaplan-Meier survival analysis suggested the overall survival of patients in the low-risk group was higher than that of patients in the high-risk group (Figure 4D). The AUC values of the ROC curves were 0.638 at 1 year, 0.722 at 2 years, and 0.834 at 3 years, demonstrating that the SLC gene family-based prognostic signature was accurate and specific in predicting survival outcomes in osteosarcoma patients (Figure 4E). The gene discussed is CCL21; the disease is osteosarcoma.