Figure 7. Quadrant distribution of alveolar macrophage (AM) subtypes for the bivariate expression of AM subtypes for the of IFI27 and APOC2 and summary of proposed AM subtype classification.

(A) AM subtype model supported by direct data. (B) Density plot showing the expression of IFI27 and APOC2 for chemokine, metallothionein, interferon, and cycling AMs. (C) Alternative AM subtype model proposed in the results section and discussion.