HPRT1 and aneurysm: Given the prominent role of inflammation in driving aneurysm progression with AngII treatment and the numerous antiinflammatory roles ascribed to Tβ4 (28, 29, 39), we also investigated aneurysm susceptibility in tamoxifen-dosed Myh11CreERT2 HprtTβ4shRNA knockdown mice, alongside Myh11CreERT2 Hprt+/+ controls (Figure 5A) and Myh11CreERT2Lrp1fl/fl mice, in order to avoid disrupting Tβ4-LRP1 function in immune cells.