A story from The Push. (Excerpted from Dome, the publication of Johns Hopkins Medicine Family.)

Alfredo Quinones-Hinojosa grew up in Mexico. Arriving in the U.S. as an illegal migrant farm worker in 1987 at the age of 19, he spoke no English and had less than $5 in his pocket. Today, Dr. Quinones - or Dr. Q as he is called by his colleagues - is a neurosurgeon, Assistant Professor of Neurosurgery and Oncology and Director of the Brain Tumor Surgery Program at Hopkins Bayview.

His first job in America was pulling weeds in tomato and cotton fields in California's San Joaquin Valley. But, Quinones' burning desire to achieve led him to the San Joaquin Delta Community College in Stockton, Calif., where he attended classes and led literacy and statistics workshops for fellow immigrants. He later attended the University of California at Berkeley, where he served as a lab assistant and a calculus and physics tutor for students from low-income backgrounds.

Inspired by the example of his grandmother, a curandera-village healer back home in Mexico-and by his own desire to connect with people in a deep way, Quinones decided while at Berkeley to pursue a career in medicine. He had set his sights on less competitive medical schools when his mentor, an administrator who ran a Hispanic Center of Excellence, intervened.

"When he saw my CV and my grades, the first thing that came out of his mouth, in a thick Mexican accent, was, ';Oh amigo, with these grades, you can easily get to Harvard.' I thought this guy was clearly living la vida loca."

It was a story he told in 1999 when he delivered the commencement address at Harvard Medical School, where he graduated cum laude and became an American citizen.

After Harvard, he completed his residency in neurosurgery at the University of California at San Francisco. Today, his lab at Hopkins Bayview is one of the most racially and ethnically diverse on campus-a consequence of his belief that "as you go up in life, you should always look back and help the people behind you."

When Quinones delivered a talk at the University of Guadalajara, it was the first time he'd been back to Mexico. "I left a peasant; I came back a professor," he says.

His own ascent was the result of tremendous energy, ambition, determination and especially, he says, the influence of mentors.

"People have given me so much. Now I am trying to give back as much as I can."