Stamos vowed to be "be by your side through it all." John Stamos is showing some brotherly love to his Full House costar Dave Coulier. After Coulier revealed today that he's been diagnosed with a "very aggressive" form of cancer,

"Full House" star and St. Clair Shores native Dave Coulier has opened up to People magazine about his recent cancer diagnosis. Coulier, 65, tells the mag he was diagnosed with stage 3 Non-Hodgkin lymphoma in October after experiencing swelling in his lymph nodes during an upper respiratory infection.

Dave Coulier has been diagnosed with stage 3 non-Hodgkin lymphoma and is undergoing treatment to battle the “very aggressive” form of cancer, according to multiple media reports.