What's your idea of a good friend? After hearing about what Kellie Pickler just did in the name of friendship, you may revise your definition. The country star/American Idol alum has just shaved off all her blond locks in support of her best friend, who has been diagnosed with breast cancer.

Pickler's buddy, 36-year-old Summer Holt Miller--a childhood friend whom Pickler refers to as a "sister"--buzzed off her own long blond hair in anticipation of starting chemotherapy this week (you can read a personal account about her journey here). Pickler, stating emphatically that "cancer does not discriminate," followed suit in solidarity.

"If this compels even one person to change their mentality toward waiting until the age of 40 for their mammogram, then it will be worth it," Miller said of her friend's gesture. Miller, who's a mom of two young children, was diagnosed in June.