Shannen Doherty's tender moment with her mum during cancer fight.

For months now, actress Shannen Doherty has been sharing the intimate details of her battle with breast cancer on her social media profiles.

Throughout her difficult ordeal, the 45-year-old former star of 90210, Beverly Hills and Charmed has been surrounded by her loved ones.

And one person who has been by her side non-stop is her mother, who Doherty affectionately named ‘Mama Rosa’ in a new Instagram tribute.

Sometimes there’s nothing like a mothers love to help get you thru. Thank you mom for always being there and being so strong for me. I love you. #mamarosa #cancersucks #fightlikeagirl

A photo posted by ShannenDoherty (@theshando) on Aug 13, 2016 at 10:34am PDT

The beautiful black-and-white photo captures a tender mother-daughter moment, with Rosa cheekily poking Doherty’s cheek as she lays in her lap.

The photo reveals a touching truth: once you are a mum, you are always a mum. Even when your child is 45.

“Sometimes there’s nothing like a mothers love to help get you thru (sic),” Doherty wrote, in a nod to her adoring mum.

A photo posted by ShannenDoherty (@theshando) on Jul 19, 2016 at 9:07pm PDT

“Thank you mom for always being there and being so strong for me. I love you.”

In moments of darkness, there truly is nothing like a mother’s love to ease the pain.

Doherty first revealed her diagnosis last year, and in July she posted heartbreaking photos of her shaving her head while undergoing chemotherapy.

This lady is pretty awesome. #lovemymom #happymothersday #mamarosa

A photo posted by ShannenDoherty (@theshando) on May 8, 2016 at 5:52pm PDT

Since then, she devastatingly announced the disease was far worse than widely thought, with the cancer spreading to her lymph nodes.

Our thoughts are with this brave woman.