Kate Middleton’s Brother Posts Heartfelt Message For His Sister Following Cancer Diagnosis

James Middleton pledged his support for his sister, Kate Middleton, Friday after the Princess of Wales went public with her cancer diagnosis.

“Over the years, we have climbed many mountains together,” James wrote on Instagram, alongside a childhood photo with his eldest sibling. “As a family, we will climb this one with you too.”

After months of intense media speculation, the Princess of Wales addressed her illness in a video shared by Kensington Palace Friday afternoon.

“In January, I underwent major abdominal surgery in London and at the time, it was thought that my condition was noncancerous,” Kate explained in the clip. “The surgery was successful. However, tests after the operation found cancer had been present.”

She went on: “My medical team therefore advised that I should undergo a course of preventative chemotherapy and I am now in the early stages of that treatment.”

Shortly after Kate’s announcement, Prince Harry and Meghan Markleissued a statement to HuffPost and other media outlets in which they expressed support for Harry’s sister-in-law.

“We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace,” the Duke and Duchess of Sussex’s statement read.

The Princess of Wales’ diagnosis was made public a little more than a month after that of King Charles III, who announced Feb. 5 that he’d begun treatment for cancer. Similarly, Buckingham Palace did not disclose what kind of cancer the 75-year-old British monarch has, or its severity.