The Royal Family just released a statement on Instagram announcing that His Majesty King Charles III has just been diagnosed with cancer.

The statement from Buckingham Palace confirmed the cancer is not related to the King’s recent treatment for a benign prostate condition. The form of cancer is still unknown.

King Charles III has been diagnosed with a form of cancer and has begun treatment, Buckingham Palace said Monday. Less than 18 months into his reign, he will suspend public duties but will continue with state business, and won’t be handing over his constitutional role as head of state.

The palace said the cancer is not related to the King’s recent treatment for a benign prostate condition. It did not say what form of cancer the 75-year-old monarch has.

The palace said “a separate issue of concern was noted” during Charles’s treatment for an enlarged prostate last month.

“Diagnostic tests have identified a form of cancer,” it said.

“His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties,” the palace said. “Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual.”