Based on limited published evidence, HAPSTR2 is a retrogene paralog of HAPSTR1 that plays a central regulatory role in cellular stress responses 1. Together with or independently of HAPSTR1, it regulates responses to DNA damage, nutrient scarcity, and protein misfolding 1. HAPSTR2 stabilizes HAPSTR1 protein through direct interaction, augmenting its stability independent of the HUWE1 E3 ligase 1. Additionally, HAPSTR2 can functionally buffer HAPSTR1 loss, safeguarding cellular resilience 1. It is primarily expressed in neural and germline tissues and select cancers 1.