Teen Mom 2 fans have watched Leah Messer face just about every challenge a mother can endure over the course of the eight years.
But perhaps nothing has brought the long-suffering mother of three more strife than the health issues suffered by her daughter Ali.
Ali was diagnosed with muscular dystrophy shortly after birth, and while her parents have consistently sought the best treatment available, there's no guarantee that her condition won't deteriorate with age.
This ongoing battle was the focus of Messer's storyline on Monday's episode of TM2, and fans were deeply moved by Leah and her ex-husband's efforts to set aside their differences in order to do what's best for their beloved daughter.
Fans have been rooting for Ali and her indomitable spirit ever since she first entered the world alongside her twin sister eight years ago.
At times, Ali's difficulty with walking and other basic motor functions may be rendered even more difficult by her twin sister Gracie's natural athleticism. But Ali couldn't ask for more supportive or encouraging siblings.
A Constant Struggle
As is the case for most single moms, Leah's life is a non-stop struggle. But her determination to secure the best possible care and adaptive equipment for Ali has never wavered.
Leah and ex-husband Corey Simms have received considerable praise for their willingness to set aside any differences they might have and focus on their daughter's health.
The Fight of Their Lives
Last night's episode saw Leah and Corey opening up about their fears for Ali's future in one of the series' most moving scenes to date.
A Worrisome Report
Ali reported to Leah that she's often in pain, her legs are tingling, and she's generally "really struggling."