MAP2K7 and thyroid nodule: In addition, due to the insertion of 2 extra amino acids, the original codon 600 (600V) in the A-loop of the kinase domain were converted into R, activating the regulation of signal transduction from RAS to MEK inside the cell.[26] Meanwhile, combined with the results of cytopathology, this nonclassical variant of BRAF might be associated with the malignancy of thyroid nodule and contribute to thyroid carcinomas.