The Slingshot program (Street et al., 2018) was used to infer trajectories within EC populations after influenza infection and demonstrated a close association between miECs and proliferating ECs (Figure 6A,B), in agreement with our data demonstrating low expression of Cd34 and other markers of Car4-high ECs as well as high expression of miEC markers in proliferating ECs (Figure 4—figure supplement 4). Here, CA4 is linked to influenza.