FARGO — The plea went out on Monday.

Seven-year-old Grantley Johnson's rare type of leukemia returned, and he would have to celebrate his birthday in the hospital.

So, why not swamp him with birthday cards?

In just hours, thousands of people heeded the call on social media to rally around the 7-year-old superhero.

He got 1,000 cards on Thursday, and greetings via social media from Minneapolis to Ellendale, N.D.

Grantley has a tough road ahead with chemotherapy and a possible bone marrow transplant at Mayo Clinic, but Thursday night it was all about Team Grantley rallying around their team captain, their MVP.

Even Grantley's friend, Henrik, who went through chemotherapy with him last year, came to cheer Grantley on.

Grantley is waiting for a match for a bone marrow transplant and his family is hoping people will take just a few minutes to sign up for a free testing kit that could save a life.

More information can be found at www.bethematch.org.