Extended Data Fig. 1: Experimental model validation.

(A) Measured weight of experimental mice used in sections at time of sacrifice. (B) Percent of total experimental mice cohort that survived to final time point at 24 weeks. (C) Schematic indicating the location of aortic root section used in the study (dashed line). (D) Aligned captured mRNA sequence of tdTomato positive cells in control (top) and Smad3ΔSMC tdTomato cells, showing absence of reads mapping to exon 2-3 which are flanked by LoxP sites. Atherosclerotic plaque in control (E) and Smad3ΔSMC (F) mice stained for phospho-Smad3 (brown), demonstrating loss of Smad3 in SMC lineage cells in the plaque. Scale bar: 50um.