Cancer Research UK on Instagram: "Could someone’s tears help detect a brain tumour? 💧 It might sound surprising, but scientists believe tear fluid could hold vital clues about what’s happening deep inside the brain. Professor Petra Hamerlik, whose own father died from a brain tumour, is leading research that could change the way we diagnose the disease. Her team developed a test that can accurately detect brain tumours in tears and now, with support from our Stand Up To Cancer UK campaign, she’