Stem-cell politics have been front and center in the race for governor, especially in TV ads.
WISC-TV examined the Mark Green ad in which former Gov. Tommy Thompson stumps for the gubernatorial candidate.
The ad takes viewers back to Wisconsin in the Tommy Thompson era. The former longtime governor and Health and Human Services secretary comes out swinging for Green.
In the ad, Thompson calls Gov. Jim Doyle a liar.
The ad starts by reminding voters of Thompson's accomplishments, and it contrasts them with Thompson's view of Doyle's four years as governor.
"Wisconsin was the envy of the nation -- created good jobs, ended welfare, improved education," Thompson says in the ad. "Now, jobs are leaving, because taxes are too high. Jim Doyle has failed us, and he's lying about Mark Green to cover it up."
A WISC-TV analysis found that this claim "needs clarification."
As past Reality Check stories have pointed out, some jobs have left, but the net effect is roughly a 170,000 job gain under Doyle's watch, according to the federal government.
As for taxes, Wisconsin is still ranked high -- seventh overall -- but that is an improvement from fourth when Doyle came into office.
Doyle's alleged lying relates to the next statement in the ad.
"Mark supports stem-cell research. Don't let anyone tell you differently. Mark helped double research funding, and he'll keep us in the lead in the search for cures," Thompson says in the ad.
WISC-TV found this claim also "needs clarification."
Notice that Thompson said stem-cell research -- not embryonic stem-cell research.
"Congressman Green has stood in the way of embryonic stem-cell research; his votes have set us back," said actor Michael J. Fox in an ad supporting Doyle.
Thompson's comments in the ad were aimed to blunt Fox's criticisms of Green in a Doyle ad.
Green -- along with most every politician -- supports adult stem-cell research.
But Green opposes using tax dollars for research on embryos when those embryos are destroyed.
This embryonic stem-cell work was pioneered at the University of Wisconsin-Madison.
Because of President George W. Bush's decision in 2001, only existing stem cell lines are eligible for federal funding. Green has backed that decision.
Last year, Congress tried to lift those restrictions on stem-cell research. Green voted "no" on the bill.
The bill passed but was vetoed by Bush.