Senescent cells are a hallmark of aging [52] and age-related diseases including obesity, T2DM, and fibrotic diseases [53,54], and triggered by various stressors shown in Pcyt2 + /- NASH (mitochondrial dysfunction, oxidative stress, inflammation, perturbed proteostasis and autophagy, epigenetic changes, and genomic instability) [55–57]. Here, PCYT2 is linked to obesity due to melanocortin 4 receptor deficiency.