Among SMA cells, Acta2 expression correlates with a veinous versus arterial distribution (Vanlandewijck et al., 2018). IC 19 represented this difference in a graded rather than categorical way, as Rgs5/Acta2 expression and IC cell scores were continuously, rather than bimodally, distributed across these cells (Figure 2C)(Vanlandewijck et al., 2018). Our data also identify new mural cell diversity. For example, cluster 1 expressed pericyte (Rgs5) and SMA (Acta2) markers. Unique markers (e.g. Aldh1a1) will help determine the anatomical identify of this population (Data S4E).
