News Ashlee Simpson Ross Sweetly Wishes Cancer Stricken Dad Joe Simpson Happy Birthday By Emily Krauser 6:40 PM PST, February 19, 2017 Now Playing hh:mm:ss 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." View this post on InstagramHappy Birthday Daddy ❤️💚💙 your my sunshine ☀️ I love you sooooooo very muchA post shared by Ashlee Simpson Ross (@ashleesimpsonross) on Feb 18, 2017 at 4:44pm PSTJoe 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. View this post on InstagramChristmas with my kids.. PaPaJoe took the first run... @jessicasimpson @ashleesimpsonross #christmas #christmastime #love #family #snowA post shared by Joe Simpson (@joesimpsonphoto) on Dec 23, 2016 at 6:16pm PST View this post on InstagramHangin at Jessica's for Christmas.... so thankful for my many blessings.... #christmas #christmastree #loveA post shared by Joe Simpson (@joesimpsonphoto) on Dec 24, 2016 at 8:06pm PSTWATCH: Evan Ross Shares Sweet Photo of Daughter Jagger Dressed as a ReindeerAfter 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.EXCLUSIVE: Joe Simpson Gushes Over Daughter Ashlee's Baby: 'Jagger is Precious!' Related GalleryStar Shots: What's On Instagram and Snapchat?