The Simpson patriarch has been battling prostate cancer since last September.
The Simpson family is celebrating the good things in life.
Ashlee Simpson Ross took to Instagram on Saturday to wish her dad, Joe Simpson, a very happy 59th birthday.
WATCH: Ashlee Simpson Celebrates Son Bronx's Birthday at Disneyland
"Happy Birthday Daddy ❤️?? your my sunshine ☀️," Ashlee, 32, captioned a pic of the two goofily embracing as she gives her dad a smooch on the head. "I love you sooooooo very much."
Joe has been battling prostate cancer since last September. In November, his rep told ET that the former manager was recovering from surgery and back to his work as a photographer. He has recently started radiation treatment to battle the cancer, according to Us Weekly.
Ashlee and Jessica Simpson's dad was grateful to spend the holidays with his girls just a couple of months ago, sharing fun photos from their festivities, which included sledding.
"Hangin' at Jessica's for Christmas.... so thankful for my many blessings.... #christmas #christmastree #love," he captioned a photo of his oldest daughter's tree.
WATCH: Evan Ross Shares Sweet Photo of Daughter Jagger Dressed as a Reindeer
After the birth of Ashlee's daughter, Jagger, in 2015, Joe sat down with ET to talk about his granddaughter, as well as his recent career change. Hear more in the video below.
