APP and Alzheimer disease: Recent research has shown that CircCwc27 directly binds to Pur-α, increasing its retention in the cytoplasm and inhibiting its recruitment to AD gene clusters, which include APP, dopamine receptor D1 (DRD1), recombinant protein phosphatase 1 regulatory subunit 1B (PPP1R1B), neurotrophic receptor tyrosine kinase 1 (NTRK1), and LIM homeobox 8 (Lhx8) [28].