BRAF and esophageal squamous cell carcinoma: The present study revealed that ESCC of Brazilian patients, who largelly present typical western characteristics, do not present mutations in hot spots of EGFR (exons 18-21), K-RAS (codons 12 and 13) and BRAF (V600E), and only a minor proportion (4%) present overexpression of EGFR or HER2.