ZEB2 and carcinoma: The availability of tRNAs that serve a particular codon is an important factor determining the rate of translation.22, 23 In line with the reduced expression of tRNAL-UAA and tRNAV-UAC genes, synonymous substitutions of UUA GGU GUA codons by CUG GGC GUG sequence (Figure 6a) strongly enhanced expression level of the ZEB2-EGFP fusion protein in different cell lines with the greatest difference observed in the epithelial carcinoma cell line MDA-468 (Figure 6c).