PPP1R13B (also known as ASPP1) is a p53-binding protein that functions as a central regulator of apoptosis through enhancement of p53-mediated transactivation of proapoptotic genes 1. The protein enhances DNA binding and transactivation functions of p53 on promoters of proapoptotic target genes in vivo 1, and is preferentially expressed in hematopoietic stem cells where it preserves genomic integrity 1. Beyond canonical apoptotic functions, PPP1R13B exhibits context-dependent roles in disease pathogenesis. In acute myeloid leukemia, impaired PPP1R13B regulation contributes to leukemogenesis and therapy resistance, with promoter methylation linked to reduced expression 1. In silicosis, PPP1R13B promotes lung fibroblast proliferation and migration through endoplasmic reticulum stress and autophagy pathways 2. PPP1R13B expression in airway epithelial cells is associated with lung function in children, with genetic variants showing effects mediated by DNA methylation 3. Genetic studies identify PPP1R13B as a novel susceptibility locus for Alzheimer's disease 4 and autism spectrum disorder 5, suggesting broader roles in neurological function. These findings position PPP1R13B as both a potential prognostic biomarker and therapeutic target across multiple disease contexts.