CCN2 and renal fibrosis: As CKD fibrosis progresses, senescent cells express and secrete pro-fibrotic factors (TGF-β, CTGF, and so forth) and pro-inflammatory factors (IL-1β, IL-6, TNF-α, and so forth), which are senescence-associated secretory phenotype factors, thereby accelerating renal fibrosis [20, 21].