MYC and pachyonychia congenita: HIF-1α upregulated circPDK1 expression under the hypoxia condition by transcriptionally activating its host gene PDK1 and hypoxia-induced exosome circPDK1 sponged miR-628-3p to release BPTF, which is required for c-Myc transcriptional activity, indicating that circPDK1 activated the BPTF/c-Myc axis to enhance pancreatic cancer (PC) glycolysis by downregulating miR-628-3p expression.