PDCD4 and esophageal squamous cell carcinoma: Exosomes containing miR-21 from cisplatin-resistant cells promote the development of cisplatin resistance in ESCC by targeting programmed cell death 4 (PDCD4) (66).Additionally, exosomal miR-193 delivery to ESCC cells increases cisplatin resistance by activating the janus kinase (JAK)-STAT signaling pathway (67).