In 2017, an International Collaborative Infantile Spasms Study (ICISS) conducted in the UK found that when steroids (ACTH or prednisolone) were combined with vigabatrin to treat IESS patients, 133 out of 186 (71.5%) enrolled patients experienced complete seizure cessation and disappearance of hypsarrhythmia EEGs after treatment. This evidence concerns the gene POMC and Hypsarrhythmia.