Timeline for rituximab therapy. Each timeline represents the treatment course for 1 patient. Panel A reflects IgG levels with normal range in gray, panel B has dots indicating months in which rituximab was given and a number indicating how many doses at 375mg/m² were given in that month. Panel C reflects total absolute B-cell numbers by CD19 staining with normal range in gray. Black arrows are the times at which plasma was collected for Ab titers and functional studies for Figures 2 and 3.