E157Q emergence in integrase has also been observed in the case of VF under a RAL-based treatment in two case reports. A case report in an highly cART-experienced patient has shown that mutation E157Q was rapidly selected and archived in intracellular HIV DNA within a short term of eight weeks of low-level replication under a RAL-based treatment . Indeed, in this case report mutation at position 157 of integrase was not present in baseline plasma virus . In a second study based on nine patients experiencing a VF under a RAL-based treatment, E157Q mutation was one of the four different resistance mutations profiles identified at VF .