(A-D) Appearance of IgG antibody to tumor cells after immunization. Pretreatment fluorescence in all patients was at the level of controls (normal human serum). Three to 6 weeks after the first immunization, four of the patients analyzed (numbers 1, 3, 5, 6) who are shown here had increased antibody binding to autologous tumor cells, shown by an increase in fluorescence activity. Increased activity persisted at least 3 months after completion of therapy. (E) For comparison, a nonresponding patient is shown.