Shimiao Ren is studying neurodegenerative diseases (NDDs) using induced neural stem cells (iNSCs) generated via direct neural lineage reprogramming. His research operates on the hypothesis that iNSCs retain partial aging features rather than resetting completely to an embryonic-stem-cell-like naive state, making them superior to induced pluripotent stem cells (iPSCs) for modeling late-onset conditions. His work specifically focuses on amyotrophic lateral sclerosis (ALS)—a rare and lethal neurodegenerative disease affecting upper and lower motor neurons—aiming to capture key ALS pathology in iNSC-derived motor neurons by preserving the critical biological factor of cellular aging.