In Katherine Heigls most famous television role, she played Greys Anatomy surgical resident Izzie Stevens who, at one point, fell in love with cardiothoracic patient Denny Duquette (Jeffrey Dean Morgan).

On her newest drama Doubt, Heigl stars as Sadie Ellis, a defense attorney who starts to fall for her client (Steven Pasquale) accused of murdering his high school girlfriend 24 years ago.

But with nearly a decade between the two plotlines, Heigl at least didnt consider her new characters shared connection to Izzie.

Thats so funny because I didnt [consider it] until you just said that, Heigl, 38, recently told The Post. It is similar in a way. Its that forbidden love thing.

The moral dilemma for [Sadie], she adds, [is] Do I risk everything and just go for it, because who knows if this great feeling, this great love will ever come around again? Or do I give it up so that I can maintain my status within my firm, my career?

Doubt was created by two former Greys Anatomy writers, married couple Tony Phelan and Joan Rater, who worked on the ABC drama for five of Heigls six seasons. And not only is Heigl older this time around, but so is her character. Sadie is a well-established defense attorney when shes tempted by love, upping the stakes for her career and her romantic future. As she hides her growing feelings for Billy (Pasquale), it strains her relationships at the firm, especially with her colleague and close friend, Albert (Dule Hill).

Along with the main storyline of Billys case (whose verdict is revealed in the season finale) and his romance with Sadie, additional closed-ended cases in each of the 13 episodes are handled by other lawyers at the firm headed by Isaiah Roth (Elliott Gould): transgender Ivy Leaguer Cameron (Laverne Cox); second-year associate Tiffany (Dreama Walker); and Nick (Kobi Libii), a former felon who earned his degree while serving time. The casting of Cox (Orange Is the New Black) is especially notable as it makes her the first transgender actor to be a series regular on a network show.

I love that Joan and Tony wanted to have a trans character on TV because they have someone they love in their life who is trans, their son Tom, who is a brilliant actor, Cox says.

They wanted Camerons trans-ness to be there, but not be the thing that we lead with and the thing that is most interesting about her.

Camerons gender is addressed briefly in the pilot, but not dwelled on, though the topic will work its way into future storylines. One of our cases is about a hate crime against a transgender person. We deal with does it make sense for Cameron to defend this woman or not? Phelan says.

The other thing that were very proud of is her character actually has an ongoing love story [which] is something people havent seen before. And it is fun and sexy and funny and touching and all the things that great love stories are.

Doubt 10 p.m. Wednesday on CBS