Talia Castellano passed away early Tuesday morning after succumbing to cancer, the Examiner reports, citing an announcement on the 13-year-old's official Facebook page. The YouTube sensation was diagnosed five years ago on Valentine's Day with stage 4 neuroblastoma, a type of cancer that develops in the nerve tissue of children and infants -- but she didn't let that ruin her spirits.

During her childhood, Castellano endured rounds of chemotherapy, surgery, stem cell transplants and radiation. The strong, young girl proved that beauty comes in all forms. She chose not to wear wigs after losing all of her hair, and her slogan was "Makeup is my wig."

Ellen DeGeneres mourned Castellano's passing on Twitter, writing, " "This year I met a very special girl, and today we lost her. Sending my heart to Talia's family...I'm so sad."

The young girl appeared on "The Ellen DeGeneres Show" after becoming an Internet sensation with her makeup how-to videos, and an honorary face for the makeup brand CoverGirl (for which DeGeneres models) in September.

“You really are quite something,” DeGeneres told Castellano. “There's a depth to your soul that is not a 13-year-old soul. You’re an old soul and you are very special and amazing, and I’m so honored that you wanted to meet me and that I got to meet you.”

CoverGirl also released a statement regarding Castellano's passing, stating, "We are honored to have known Talia and grateful for all the ways she showed us what true beauty means. She inspired millions with her strength, personality and talent. Talia has touched our CoverGirl family forever, and we're thankful to have been a part of her life. Our hearts go out to her family and friends during this difficult time."

Castellano used YouTube as a way to inspire other women in similar daunting circumstances. She had her own channel, which she used to post makeup tutorials and words of inspiration, drawing 60,000 subscribers and more than 14 million viewers.

On her Facebook page, “Angels for Talia,” a family representative wrote, “‪#‎prayfortalia It is with a heavy heart that we share with all of you that Talia earned her wings at 11:22 a.m. Please lift her beautiful soul, her beautiful light to heaven and please send your love and prayers to her family during this most difficult time.

"God speed little one, may you be free from pain and suffering, may your soul feel the light and love that you brought to so many of us on this Earth during the short time you were here with us. We will miss you more than you will ever know, baby girl.”