Based on the reported interaction between SP1 and TUG1 [13], the current study set out to explore this interaction in regard to CRC, and uncovered that TUG1, upon activation by transcription factor SP1, could bind to miR-421 to up-regulate KDM2A expression and activate the ERK pathway, consequently facilitating the progression of CRC (Fig. 7). The gene discussed is TUG1; the disease is colorectal carcinoma.