The knockdown of circ_0000215 remarkably represses the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of NPC cells, via functioning as a ceRNA to regulate miR-512-5p and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1). Here, PIK3R1 is linked to nasopharyngeal carcinoma.