Researchers have built disease models using induced pluripotent stem cell (iPSC)-derived motor neurons exposed to patient serum containing anti-GM1 IgM antibodies. These models reproduce complement activation and structural neuronal damage seen in MMN, giving scientists a human cellular system to study disease mechanism and test candidate therapies (including empasiprubart) without needing nerve biopsy tissue. This is a foundational tool for future target discovery and drug testing in a genuinely human — not just animal — system.