In season seven, when Cuddy, who is House's girlfriend at this point, has a brush with death, House goes back on Vicodin in order to cope with the fear of losing her. Near the end of season seven, House finds out the experimental drug he had been using caused fatal cancerous tumors in all of the lab rats in the experiment. He gets a CT scan of his leg and finds three tumors close to the surface of the skin in his leg. He goes home, cleans his bathroom, and attempts to perform surgery on himself to extract the tumors in his bathtub.