Photo taken by Kate released to mark Prince Louis’s 6th birthday

Prince Louis, the youngest and most rambunctious son of Prince William and Kate Middleton, is 6! The Palace marked the occasion with a candid photo snapped by Kate, who is undergoing treatment for cancer. NBC’s Molly Hunter reports for TODAY. » Subscribe to TODAY: @TODAY About: TODAY brings you the latest headlines and expert tips on money, health and parenting. We wake up every morning to give you and your family all you need to start your day. If it matters to you, it matters to us. We are in the people business. Subscribe to our channel for exclusive TODAY archival footage & our original web series. Connect with TODAY Online! Visit TODAY’s Website: Find TODAY on Facebook: Follow TODAY on Twitter: Follow TODAY on Instagram: » Stream TODAY All Day: About: TODAY All Day is a 24/7 streaming channel bringing you the top stories in news and pop culture, celebrity interviews, cooking, and more. All in one place. #royalfamily #katemiddleton #princelouis