CDKN1A and cancer: Since CDKN1A, TP53INP2, and PAQR3, were all associated with the development of cancer, we used qRT-PCR to demonstrate that the expression levels of PAQR3 were significantly downregulated by the silencing of hsa_circ_0043280 and dramatically upregulated after the overexpression of hsa_circ_0043280 in CCa cells (Fig. 4B).