As mentioned in the introduction, several approaches have been used for epitope prediction; the so-called scale-based approach exploited one or more scales of amino acid properties to weight each residues of the sequence of interest [2, 18, [25] [26] [27] [28] . The use of multiple scales was essential to predict epitope location reliably, as reported by Blythe et al. [29] . Therefore, we considered some of the most promising amino acid properties reported in these studies, by resorting to a set of widely used scales (i.e. the five scales reported in Table 1 ) [9-13]: