S100A9 and nasopharyngeal carcinoma: Simultaneously, S100A9 expression is also elevated in the tissues or sera of colorectal carcinoma (Huang et al., 2019), hepatocellular carcinoma (Zhong et al., 2022), gastric cancer (Fan et al., 2012), nasopharyngeal carcinoma (Hu et al., 2021), and renal cell carcinoma (Zhang et al., 2015), consistent with low disease-free, overall, and recurrence-free survival periods, which can also be used as a powerful diagnostic indicator (Koh et al., 2019; Koh et al., 2021).