The FDA has approved the expanded use of GSK's Wellcovorin (leucovorin) for the treatment of cerebral folate deficiency (CFD), a rare disorder that occurs in patients with a confirmed variant in the folate receptor 1 gene[1]. It is the first drug approved for this disease, which is characterized by severe developmental delays, movement disorders and seizures[1]. Wellcovorin was originally developed by GSK and was marketed under its brand name between 1983 and 1997[2]. Currently, leucovorin is available in the US as a generic drug[2]. The FDA asked GSK to update the information on the drug packaging based on data from case reports of patients with genetically confirmed CFD[2]. This decision is part of the FDA's initiative aimed at re-evaluating older drugs in order to find new possibilities for their use in the treatment of chronic diseases[2]. GSK has a minimal role in this matter and has no commercial or scientific interest in this indication[6].