And circUBE4B encodes a new procancer peptide (circUBE4B‐173aa) and promotes the expression of phosphorylated MAPK1 by directly binding to MAPK1, which stimulates downstream MAPK/ERK signaling axis and promotes tumor malignant progression in the esophageal squamous cell carcinoma (ESCC).95 Here, MAPK1 is linked to esophageal squamous cell carcinoma.