PTBP1 and infection: Thus, by expressing an hnRNP I protein tagged with the TAT peptide motif (hnRNP ITAT) we may reconstitute the hnRNP–vRNA interaction, enabling direct comparisons of infections with the native hnRNP I interaction, no hnNRP I interaction, and a forced hnRNP I interaction to determine the explicit importance of hnRNP–vRNA binding.