Buffy The Vampire Slayer actress Sarah Michelle Gellar is surely a true friend when it comes to uplift the spirits of Shannen Doherty, who is battling breast cancer. The actress posted a touching tribute to her friend on Instagram and shared that Doherty is her "true friend".

Gellar posted an image of the Beverly Hills star and supported her in the fight against cancer. She wrote: "My #mondaymuse (and really every day #muse) is my brave friend @theshando, I've always said she is one of the most loyal friends I've ever known, and now while she is facing the toughest journey of her life, she is sharing it with friends she has never met in the hopes of helping other people who are going through the same struggle. That's a true friend #F—Cancer."

My #mondaymuse (and really every day #muse) is my brave friend @theshando. I've always said she is one of the most loyal friends I've ever known, and now while she is facing the toughest journey of her life, she is sharing it with friends she has never met in the hopes of helping other people who are going through the same struggle. That's a true friend #FuckCancer

A photo posted by Sarah Michelle (@sarahmgellar) on

Doherty was equally moved by her friend's touching gesture and felt 'blessed' to have her former co-star as a "great friend".

She posted the same picture on the image sharing website and wrote: "I'm starting #totaltuesday and dedicating it to @sarahmgellar. Why? Because she's the total package. Smart, funny, beautiful and a great friend. She's that friend that is always there when you need her no matter what. Loyal and loving to the bone. I am blessed for many reasons and she's one of them."

I'm starting #totaltuesday and dedicating it to @sarahmgellar. Why? Because she's the total package. Smart, funny, beautiful and a great friend. She's that friend that is always there when you need her no matter what. Loyal and loving to the bone. I am blessed for many reasons and she's one of them. Love you SMG. #cancersucks #fightlikeagirl #friendshelpcancersuckalittleless

A photo posted by ShannenDoherty (@theshando) on

Doherty was diagnosed with breast cancer in March 2015, but during an interview with ET Online, the 45-year-old actress announced that her cancer had spread to her lymph nodes. She has already undergone three out of eight rounds of chemotherapy and a mastectomy.

In one of her previous Instagram post, the actress had gushed about her husband Kurt Iswarienko for being a strong supporter in her cancer battle. "He loves me with pink hair or no hair. I'm blessed to have such a strong support team starting with @kurtiswarienko who loves me more every second. Can't imagine my life without him. Cancer is not pleasant but it can bring out the best in relationships or the worse. Thankfully, it has made our marriage stronger," she wrote.