BMP1 and chronic kidney disease: Even when we compared CKD subgroups (CKD 1–2 or CKD 3–5) with CTRL for each area, frequencies of BMP-1 positivity were similar (CTRL vs. NKB-CKD 1–2, CTRL vs. NKB-CKD 3–5, CTRL vs. TXCI-CKD 1–2, and CTRL vs. TXCI 3–5; all p > 0.05), with only one exception for DT area, where frequency of BMP-1 staining was significantly higher in NKB-CKD 1–2 than in CTRL (0% vs. 47%, p = 0.035).