Accumulating evidence reinforces the theory that cancer is developed and maintained by a subpopulation of cancer cells with stem cell properties. These cancer stem cells (CSCs) are typically in a quiescent state, making them resistant to standard therapies and responsible for disease relapse. The ERC-funded SeleCStem project aims to develop innovative strategies to target CSCs effectively by exploiting the enzyme aldehyde dehydrogenase (ALDH), which is overexpressed in CSCs across various cancers. The research team will harness the enzyme’s activity to selectively release drugs within CSCs and combine it with light-mediated inhibition of ALDH in tumours.