Abstract: When HIV-1 strains were selected for resistance against three different HEPT derivatives [i.e., HEPT and its derivatives 5-ethyl-1-ethoxymethyl-6-benzyluracil(E-EBU) and 5-ethyl-1-ethoxymethyl-6-(3,5-dimethylbenzyl)uracil (EBU-dM)], HEPT selected for the mutation
188-Tyr-->His, E-EBU for 181-Tyr-->Cys, and E-EBU-dM for 106-Val-->Ala, in the
reverse transcriptase of the mutant viruses.