CTLA4 and neoplasm: To determine if knocking out apoE in tumor cells induced immunogenicity, we vaccinated wild type and apoE-/- mice (Figure 10A) or wild type and lrp8-/- mice (Figure 10B) with WT B16 or apoE-/- B16 tumor cells and CTLA4 Ab and then collected splenocytes from these vaccinated mice 6 days later.