Upon his death in 1956, he passed it on to Jean, who, with his wife, supported local artists such as Eugène Leroy and Arthur Van Ecke, thus helping to anchor the museum in both local and international history. In 1976, Jean Masurel donated it to the Lille Urban Community.
But what makes the LaM truly unique is its collection of art brut, one of the richest in Europe. Thanks to a donation from the Aracine association, the museum was able to incorporate works by Henry Darger, Auguste Forestier, Madge Gill, and many other artists, often self-taught and marginalized, whose works today fascinate collectors, researchers, and visitors alike. In 2007, an extension was created to provide a dedicated, immersive, and poetic space for this collection that breaks new ground in art. A place where visitors can stroll among works in a wide variety of forms (furniture, texts, sculptures, etc.).