PACS2 and intervertebral disk degenerative disorder: CD90‐positive NP cells (NPCs) were previously identified as progenitor cells based on scRNA‐seq analysis, flow cytometry, and multipotency assays.[16] Further analysis revealed that the proportion of CD90+PACS‐2+ NPCs was higher in mild IDD (Pfirrmann II/III) than in severe IDD (Pfirrmann IV/V) (Figure 1R,S), suggesting that loss of CD90+PACS‐2+ NPCs may be associated with IDD progression.