RB1 and acute kidney injury: The current research demonstrates for the first time that FFAR4 is a key determinant of cellular senescence both in injured kidneys of AKI mice and TECs, as suggested by the activity of SA-β-gal, the biomarker p53, p21, Lamin B1, ɣH2A.X, phospho-Rb change, and the secretory phenotype IL-6 expression.