Il6, Stat3 and Tnf, which were enriched in cluster 3 (Figure 3B) of the aging kidney, have been linked to renal inflammation and fibrosis, contributing to CKD progression through excessive cytokine signaling and extracellular matrix accumulation (Kandemir et al. 2022; Zheng et al. 2019). Here, IL6 is linked to chronic kidney disease.