APOA1 and esophageal squamous cell carcinoma: analyzed the serum proteomic profiles before and after radiotherapy of Kazakh esophageal cancer patients in Xinjiang and found 21 significant different expressed protein spots peaks; Clusterin (CLU) was detected as a radiation resistant biomarker, and Apolipoprotein A1 (APOA1) was discovered as a serum biomarker of esophageal squamous cell carcinoma (62).