After mislabeling Biden's stage 4 prostate cancer diagnosis as "stage 9," which does not exist, Trump again raised questions about the former president's cognitive health

Donald Trump reacted to the news of Joe Biden’s prostate cancer diagnosis by flexing his own clean bill of health Monday. The president also followed his son’s lead in casting doubt on how long his predecessor had known about his “Stage 9” cancer.

Donald Trump sparked online ridicule after claiming Joe Biden has Stage 9 cancer, a non-existent medical term. Trump questioned why Biden's physical didn't include cognitive tests, boasting about his own.