Viral Epidemiology Signature Pattern Analysis (VESPA). The query sequence is the SVR group while the background sequence is the non-SVR group. The dots (.) in the signatures indicate that the two sequences agree in those positions while the letter indicates a statistically significant position. A) In HCV subgenotype 4a, no signature pattern between the two groups of responders and non-responders was found. B) HCV subgenotype 4d results revealed one signature pattern between the query signature (SVR) and Background signature (non-SVR) in genotype 4d. This signature is at position 70, where it is associated with amino acid Arginine (R) in SVR group compared to amino acid Glutamine (Q) in non-SVR group. Statistically significant variations were calculated with a threshold of P < 0.05.