ZFAS1 and colorectal carcinoma: To further elucidate the underlying mechanism of DDX21 in the context of lncRNA-ZFAS1 mediated CRC development and its regulation manner, we employed catRAPID (http://service.tartaglialab.com) to evaluate the interaction propensity and power between the lncRNA-ZFAS1 nucleotide index and the DDX21 residue index (Figure 4A).