Codons chosen due to mutation bias for G+C lie under the curve of predicted values, if the value lies above, they are selected by natural selection (Vicario et al., 2007). Our analysis showed that all the points were below the expected curve, suggesting that the codon bias in the 132 RABV ‘G’ gene sequences are affected by mutation (Fig. 2A). The analysis of ‘N’ gene of RABV also showed the similar pattern suggesting the observed codon bias is mutational (Fig. 2B).