To further evaluate the association between the serum DKK1 levels and CKD progression, the enrolled CKD patients (n = 50) were initially divided into two equal groups based on their serum DKK1 levels, namely, the DKK1-high group (≥1440.0 pg/mL, n = 25) and the DKK1-low group (<1440.0 pg/mL, n = 25). The gene discussed is DKK1; the disease is chronic kidney disease.