ADK and breast carcinoma: In addition, to identify possible divergent roles of ADK isoforms, we conducted a follow-up in vitro study using our established CRISPR/Cas9 gene-editing approach to knockdown ADK-L or ADK-S isoforms in cultured MDA-MB-231 cell lines, and further evaluated the effects of manipulating each ADK isoform on the cell growth, viability, migration, and invasion ability of cultured breast cancer cells.