DDX21 and colorectal carcinoma: The IHC staining showed that DDX21 was significantly upregulated in CRC tissues compared with normal tissues (Fig. 1D), and we found that increased DDX21 expression was positively associated with the malignant phenotype of CRC, such as tumor diameter (p = 0.0112), depth of invasion (p < 0.0001), lymph node metastasis (p = 0.0064), distant metastasis (p = 0.0027), and TNM stage (p = 0.0140), suggesting that DDX21 plays an oncogenic role in driving the progression of CRC (Additional file 1: Table S1).