CTLA4 and xanthoma: The morphological classification of the plaque phenotype demonstrated that the incidence of intimal xanthomas was decreased (54% (control) vs. 25% (αCTLA4)) in anti-CTLA4-treated mice, whereas pathological intimal thickenings (33% (control) vs. 46% (αCTLA4)) and fibrous cap atheromas (13% (control) vs. 29% (αCTLA4)) were increased (Figure 4C).