It wasn’t your typical mob scene when the S.F. Giants three-time World Series Champ and MVP catcher Buster Posey paid a recent visit to UCSF Benioff Children’s Hospital. The hospital’s Creative Art Studio was filled with young cancer patients dressed in an array of Posey 28 jerseys and hospital gowns. Along with their families and hospital staff, some kids were accompanied by portable poles entwined with feeding tubes, monitors and IVs — whirring, dripping and calculating precise medical doses required to battle pediatric cancer.

In April, Posey and his wife, Kristen Posey, announced the formation of the Posey Family Foundation, dedicated to raising awareness and funds to aid research in the fight against pediatric cancer.

UCSF Benioff Executive Director Kim Scurr applauded their efforts, as almost half the nation’s sick children receive government assistance for which hospitals are reimbursed at a very low rate.

“Childhood-disease researchers are challenged as they’re typically only funded by charitable organizations or subject to budget cuts incurred by the National Institutes of Health,” she said. “That’s the very essence of what we do here at Benioff Children’s Hospital: find treatment and cures. And through our work, we’re certain research does translate to cure.”

Pediatric cancer is the fourth-leading cause of death among children. Yet from every dollar the federal government spends on overall cancer research, that disease receives just 4 cents.

Those stats don’t sit well with the Poseys, proud parents to healthy 5-year-old twins. Kristen Posey was also inspired when she connected with Melissa Wiggins, whose son was diagnosed with neuroblastoma when he was just 20 months old. When the Poseys learned that Cannon Wiggins is just two days older than their twins, they were spurred to action.

The Poseys’ efforts include ongoing hospital visits, a pediatric-cancer awareness day at the ballpark, and a New Era BP28 fundraising baseball cap.

They’ve also joined forces with the Giants (which last fall received the MLB Commissioner’s Award for Philanthropic Excellence) to host monthly ballpark pre-game Posey visits for cancer patients and families undergoing treatments at local hospitals.

“Buster and Kristen approached us eight months ago with their philanthropic effort and asked for our support,” toasted Giants CEO Larry Baer. “I was touched by their passion and authenticity. It’s very rare for a professional athlete and his family to express such heartfelt, long-term intention off the field.”

Posey and his wife also inspired the Giants to create the team’s first-ever, player-driven gala (in conjunction with the V Foundation, which also supports cancer research) at the ballpark.

“Anybody who is a parent has a primal, instinctual feel to protect their children,” Buster Posey explained, standing on the field at the gala dressed in a natty non-game business suit. “A lot of these sick kids and their families are in situations where they throw their hands up in frustration after doctors advise them, ‘This treatment might work, or it might not.’

“For me and Kristen, that’s a scary thought,” he continued. “Anything we can do to alleviate a little of those families’ fear and form a community feels like the honorable thing to do.”

Two hundred and twenty-five supporters agreed, ponying up $25K for swanky tables — with all event costs underwritten by the Poseys, the Giants and Bon Appetit catering — set on the ballpark’s Club Level.

Dulcet-voiced Giants announcer Renel Brooks-Moon emceed as former Giants relief pitcher ( gosh, we miss him!) Jeremy Affedlt threw verbal Ks to inspire live-auction bidders. The Poseys’ pal, singer Phillip Phillips, wowed with a stellar set. And ESPN sportscaster and V Foundation advocate Dick Vitale endlessly prowled the tables imploring, in his signature style, for donations.

At night’s end, the Poseys’ inaugural philanthropic event raised $550K for the V Foundation to distribute among Bay Area pediatric-cancer research programs.

Catherine Bigelow is The San Francisco Chronicle’s society correspondent. Email: missbigelow@sfgate.com Instagram: @missbigelow