Time course of loss and recovery of lymphocyte populations during chemotherapy and 1 year of follow-up in the FLAC/taxol study, showing that CD4 recovery postchemotherapy lags behind that of other lymphocyte populations. The average percentage of recovery of lymphocyte populations as compared with pretreatment levels in each patient was determined. When patient data for more than one assay was available within the 3-month time periods (see Fig 4), only that assay closest to the 3-month interval was used in this calculation. (*) Time points at which percentage recovery of lymphocyte populations differs significantly from pretreatment levels.