Samantha Harris Hits Pavement for Good Cause

Philanthropic runners laced up and rocked out in San Diego on Sunday. ET's Samantha Harris boosted their energy as host of the 13th annual Rock 'n' Roll Marathon & Half Marathon to Benefit The Leukemia & Lymphoma Society.

She took the cause close to heart, revealing, "My grandfather has been suffering from lymphoma for a long time…I am honored to be a part of it."

Amongst the field of a whopping 30,000 entrants were some visitors from Sin City. "The Elvis impersonators are quite hilarious," Samantha laughed. "I love that they are running in this marathon. It's fantastic."