A team of researchers at Cardiff University has discovered stem cells in the cheek can be used to supress the immune system. It should help patients with certain types of diabetes, and those whose bodies reject organs after transplants.
It'll be several years before a treatment's developed but the scientists say it's a real breakthrough.
More top news
The Severn tolls will be abolished by the end of next year, the Secretary of State for Wales Alun Cairns has announced.
So we end the week with a warning! There'll be heavy rain and strong winds today, with unsettled weather remaining over the weekend!
There'll be dry and clear spells at times with a scattering of heavy showers thrown in! It will feel fresher too.