PVT1 and nasopharyngeal carcinoma: For example, circPVT1 can prevent c‐MYC ubiquitination and degradation, and c‐MYC further enhances the transcription of PVT1 and recruits SRSF1 to facilitate circPVT1 splicing, establishing positive feedback and promoting nasopharyngeal carcinoma (NPC) invasion and metastasis123 (see Figure 4A).