Researchers observed positive interactions, in which one disease favours the onset of another, such as between asthma and Parkinson's disease; and negative interactions, in which some groups of patients with one disease may be protected from developing others, such as between cancer and Huntington's disease.

Clinicians typically classify meningiomas — the most common type of brain tumor — into three grades, ranging from slow-growing to aggressive. But a new multi-institutional study suggests that appearances may be deceiving. If a tumor shows activity in a gene called telomerase reverse transcriptase (TERT), it tends to recur more quickly, even if it looks low-grade under the microscope.

Scientists have found a way to stop brain cancer cells spreading by essentially ‘freezing’ a key molecule in the brain.