Three studies [21, 49, 51] reported tubular damage score found that the blockade or knockout of CB1 group could significantly reduce tubular damage in renal dysfunction animals compared with the control group (Fig. 3E, 4 items, n = 74; SMD, − 2.29; 95% CI − 3.56 to − 1.01; P = 0.0005; I2 = 68%). The gene discussed is CNR1; the disease is Abnormal renal physiology.