New F2 champion Dean Stoneman has pulled out of racing for 2011.
The 20-year-old Briton, who tested with the F1 team Williams in Abu Dhabi last November, has been diagnosed with testicular cancer.
He had intended to progress to the Renault World Series this year but instead will "concentrate his complete attention on returning to full health", a statement on his website said.
"Specialists have made the diagnosis early and are confident that he will make a full recovery, with treatment scheduled to begin with immediate effect," added the statement.
Cycling legend Lance Armstrong is a famous survivor of testicular cancer.