The TIPI2 study is a blood and tissue collection protocol to create an annotated biorepository to support research in drug-resistant epilepsy. The aim of the study will be to identify new pathophysiological pathways. For this purpose, the investigators will investigate with a multimodal approach blood and brain samples from patients undergoing a surgery for focal drug-resistant epilepsy. The adult patients will be enrolled either during the pre-surgical evaluation or right before the surgery.