Kellie Pickler shaved her head this week, and it wasn’t after a Britney Spears-like meltdown. The country singer shaved her head because her friend, Summer Miller, starts chemo for breast cancer this week.

Kellie has been friends with Summer since they were kids, and calls Summer her “sister”.

Kellie shaved her head on Good Morning America. See the video here.

Summer Miller is just 35 years old, and said, “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.”

After shaving her head, Kellie Tweeted, “I cannot thank everyone enough for all the love and support you’ve given Summer. Chemo starts tomorrow. #SayAPrayerForSummer.”

See a picture of Kellie and Summer after shaving their heads.