DKK1 and non-small cell lung carcinoma: CircRNAs can inhibit NSCLC tumorigenesis and progression by regulating the circ_0018414/miR-6807-3p/dkk1/Wnt/β-catenin, circ_0006427/ miR-6783-3p/dkk1/Wnt/β-catenin, and circ_0007059/miR-378/Wnt/β-catenin pathways and the cir-ITCH/miR-7/miR-214/ITCH/Wnt/β-catenin axis.