DDX21 and cancer: Furthermore, we found a statistically significant positive correlation between DDX21 expression and the approximated infiltration value of cancer-associated fibroblasts for TCGA tumors ACC, BRCA-LumA, CESC, COAD, GBM, HNSC (HPV+/−), KIRP, LIHC, LUAD, LUSC, MESO, OV, PAAD, and THYM but noted a negative correlation for STAD (Figure 7A).