Unexpectedly, one FOLR2-Mφ subcluster featuring the highest overall CMKLR1 expression (Fig. 1F) was overrepresented in IPF samples (Fig. 1G) and had several high confidence connections directly to subclusters of the SPP1-Mφ IPF profibrotic archetype (Fig. 1E). Here, SPP1 is linked to idiopathic pulmonary fibrosis.