CCL21 and neoplasm: To examine the expression patterns more closely, we analyzed the proportion of patients with varying expression levels of 25 selected SLC proteins in tumor versus normal tissues, as shown in Figure 3B. Notably, a high proportion and elevated expression levels were observed in the following proteins in HNSC: SLC16A3, SLC53A1, SLC25A32, SLC2A3, SLC38A7, and SLC7A5.