DevilDriver frontman Dez Fafara has made good on his promise to help out his sister Kerri by writing and releasing a benefit song about her that will help raise funds for her breast cancer treatment.

Fafara states, "'Dark Meadowlark' is about my sister, who is a ray of sunshine, but has a dark sense of humor, much like myself, thus the [track title]." The singer also tweeted, "Love and light to my sister Kerri, diagnosed with breast cancer. She has always had my back since we were kids."

Kerri says, "As soon as my big brother heard … he unleashed the most powerful healer there is - compassion. Not a day has passed without a message of love and encouragement from him. That's really what gives us the strength to take the next step - knowing that someone cares about us 100 percent."

Even with insurance, Kerri is unable to cover the costs of surgery, chemotherapy and radiation that is yet to come. In addition, she's relocated from Idaho to California to be closer to the treatment center.

To make a donation, you can check out Kerri's Microgiving website here. To purchase 'Dark Meadowlark,' click here.