Andrew McMahon (born September 3, 1982) is a Maverick recording singer/songwriter and the vocalist, pianist and main songwriter for the band Jack's Mannequin and the Geffen/Drive-Thru Records band Something Corporate. He was diagnosed with Leukemia on June 1st, 2005. On August 23rd, 2005, Andrew received a stem cell transplant; the donor was his sister Katie McMahon.