Figure 5. 5a simulates combined drug treatment data reported for a patient (18; Figure 1d). The treatment begins with the uninfected CD4+ T-cell count at 306/mm3, the infected CD4+ T-cell count at 10/mm3, and the virus level at 21/mm3 (these values are obtained from the simulation in Figure 1a, b at 5.75 years). The treatment parameters are c1=2.0, c2=1.0, c3=.15, the resistance threshold value is V0=3.0, and the resistance mutation parameter is q=10-7. Resistance does not develop, and the therapy results in remission. The plasma viral level shows a two-phase exponential decay, which is attributed to a slower drug-induced inhibition of virus in the lymphoid compartment. In 5b, the treatment simulation in 5a is continued for 78 weeks and then stopped. The virus population rebounds rapidly when treatment stops.