MITF and esophageal squamous cell carcinoma: CLK4 was also found to be extensively downregulated in esophageal squamous cell carcinoma (ESCC) cells and patient samples due to the methylation of its promoter.126 Mechanistically, CLK4 phosphorylated microphthalmia-associated transcription factor (MITF) at Tyr360 to promote the autophagy degradation of MITF.