Neurobiologists argue that our neocortex, rich in neurons, distinguishes human cognition, enabling abstract thinking, art creation, and complex language. Dr. Mareike Albert, leading an international team at CRTD of TUD Dresden, identifies a new factor possibly contributing to human neocortex expansion. Published in the EMBO Journal, their study compares human and mouse brain development, revealing a human-specific factor, epiregulin, promoting stem cell division and neocortex expansion. Utilizing 3D brain organoids, mimicking human brain complexity, they demonstrate epiregulin’s role in stem cell expansion. This research sheds light on human brain evolution and may inform mental health disorder treatment.