Whether it's brotherly love or just being a "big brother," there are some responsibilities that one just inherits.
Like - nobody or anything messes with a younger sibling.
Not even cancer.
"I was in shock when I was told," says 13-year-old Rylee McGuire, a seventh-grader at Blue Earth Middle School.
Last November, 7-year-old Sullivan "Sully" McGuire - son of Ryan and Melissa - was diagnosed with osteosarcoma in his left leg.
Rylee wasn't about to sit idly by and do nothing.
Sully's fight was going to be his, too.
"I miss him and his personality when he's gone. He's always playing jokes," says Rylee. "He's a meanie."
Rylee had an idea to have ribbons made to show support for his brother. That led to bracelets and formation of a group called Sully's Warriors.
The Buc Wrestling Boosters had green "Sully's Adventure" T-shirts made and were worn by wrestlers and sold for $10 each to raise money for the family.
This Saturday a benefit hosted by Sully's Warriors is going to be held from 4-8 p.m. at the Blue Earth Fire Hall.
"The support from people has been awesome. You don't have the words to try and thank people," says Ryan, Sully's father.
"It's not easy accepting help and money from people. But, it's very appreciated," he adds.
Melissa is overwhelmed by the number of people aware of Sully's battle against cancer.
"Someone sent bracelets to people they know in Poland and there are people in Laurens, Iowa, who know about Sully," she says. "People we don't even know are praying for him and us."
Before the start of the legislative session, Minnesota lawmakers said a prayer for Sully.
He's even received notes from District 1 Congressman Tim Walz and U.S. Sen. Amy Klobuchar.
At the wrestling State Tournament held Feb. 28 through March 2 in St. Paul, some Buc fans instead of wearing the school colors of maroon and gold - donned a green "Sully's Adventure" T-shirt.
And, the Jackson County Central Huskie team wore the T-shirts during their competition, huddled in a circle and said a prayer for Sully after winning the Class A team title. "That's what I was told," Melissa says with a smile.
The McGuires work for Blue Earth Area Schools, Melissa as the K-8 principal and Ryan, a maintenance specialist.
Both can't say enough about support and concern shown by co-workers and administrators.
"If I have to leave, there aren't any questions asked," says Ryan.
Melissa says prayer and friends have gotten them through the tough time she describes as "a bump in the road."
"Our neighbors and others have done those little things we may have overlooked. It's been a real relief," she says.
Ryan has been through this before, losing his mother to cancer when she was 63 years old and a sister, who was 38.
"It was 12 years ago. They were buried 10 days apart," he says, wiping his eyes.
The future for the McGuires is looking brighter.
"On Feb. 13 at 9:52 a.m. Sully became cancer-free," says Melissa.
On that day, after 10 weeks of chemo therapy, Sully underwent six hours of rotation-plasty surgery on his leg.
A tumor was at the bottom of his femur - the main thigh bone - so a specialist removed bone and muscle above and below the knee.
The lower part of Sully's calf, the ankle and foot were then turned 180 degrees and attached to the high bone and muscle.
His ankle is now his knee and once he gets stronger, Sully will be able to wear a prosthetic lower leg over it.
Melissa says her son has gotten encouragement from an unexpected ally.
Shanna Decker, formerly of Plainview, had the same cancer in her left leg, too.
She also was 7 years old and had to have the same surgical procedure as Sully.
Now she's 22 years old and works at Mayo Clinic and visits with Sully whenever she can.
"She's been a mentor to him. She knows what he's going through and can tell him what to expect when he gets his leg," she says. "My mom says Shanna has a bond with Sully that some of us will never have."
Sully still has about 20 more weeks of chemo.
When he returns home from getting treatment, he likes to stop by the school to see his classmates, depending on how he's feeling.
For now, a teacher comes to his house but the McGuires hope their son is well enough to go back to school by the end of this year.
The family is taking it one day at a time.
"He's making progress every day. God has chosen him to do something special, we're waiting to see what it is. Maybe he'll inspire and help someone who has some type of adversity," says Melissa.
The McGuires should know Sully already has.
Saturday's benefit also will mark Sully's eighth birthday.
It's going to be quite a party.