WATCH: 'Honor' to Be on Transparent, Jeffrey Tambor Tells Janet Mock

Best-selling author and transgender activist Janet Mock, in her first appearance as an Entertainment Tonight special correspondent, delved into the issue of cisgender (nontrans) actors playing trans roles and a host of other topics in an interview with Transparent star Jeffrey Tambor.

Mock was quick to bring up the controversy of Tambor's casting as transgender woman Maura on Transparent. "There's been a lot of nontrans actors who have played trans roles who have been, you know, award-worthy," Mock said, citing some well-known examples: "Felicity Huffman in Transamerica. Jared Leto last year with Dallas Buyers Club. How do you feel embodying this role?"

"I always feel humbled. People say they would rather have a transgender [person] play that role," he told Mock. "I feel that they are right. And that I understand, because there has been such a ... they have been so maligned. If you heard, 'Jeffrey Tambor is about to play Maura,' what would you think? And so, even just this morning, I was doing this thing. Everyone just titters at the idea at first, and then they see it. And they see this scene, where she comes out, and everyone just calms down."

The scene Tambor refers to, played by ET for viewers of the interview, is from the beginning of the second episode, when Maura comes out to her eldest daughter. Sarah, played by Amy Landecker, is stunned to see her father, Mort, dressed en femme.

She asks, in a confused, slightly mortified tone, "Are you saying you're going to be dressing up like a lady all the time?"

Tambor, playing Maura, replies with a smile and a chuckle that reveals her relief at finally revealing this lifelong secret.

"Honey," Maura tells Sarah, "all my life, my whole life, I've been dressing up like a man." Maura takes Sarah's hand and delivers the line that has resonated with so many transgender viewers.

"This is me."

"That was so powerful," Mock told Tambor. "And I've seen many people in the community talk about that," to which Tambor expressed both surprise and gratitude.

"That moment," she said. "That line alone; it shifted the way that people had conversations around this idea of trans people coming out, and telling their truths and living authentically."

Mock asked Tambor what were some of the biggest lessons he'd learned about the trans community by playing Maura. His response, after a deep breath: "Lives are at stake. The conversation needs to go forward. And there needs to be freedom. Life, liberty and the pursuit of happiness is part of our constitutional rights. And it belongs to everybody."

Both also said they were honored to meet the other. "The honor of being able to play Maura is transformative," Tambor, who is Golden Globe-nominated for the role, told Mock. "I'm 70 years old. I should be in a reading room, reading Dickens or something."

Following the interview's broadcast last Thursday, Mock wrote to her followers on Facebook, "We must continue to be our own heroes and write the words and create the images that show who we truly are. Don't let anyone tell you that what you have to say doesn't matter (I've been there!), don't take on their poisonous desire to make you invisible (I *see* you!), don't internalize their hate and rage (act with love, shine your light!). You matter, and your people are waiting to hear from you, to see themselves reflected, affirmed, validated. This message is for you as much as it is for me, and that's why I'm writing it down in this note. To make myself accountable to my feelings, my truth. Keep shining and creating."

And Mock is going to do just that. MSNBC has tapped the best-selling author of Redefining Realness to be part of its new video-streaming project, Shift by MSNBC, in which it will offer online-only content that could eventually get picked up for TV broadcast, depending on popularity with viewers. Mock will host So Popular! which "looks at celebrity and pop-culture news through a progressive lens," Variety reports. Gay anchor Thomas Roberts will also participate in Shift, which launched today, hosting Out There, a program on LGBT issues.

Mock will appear on ET again as well. "I love working with Janet," Brad Bessey, a gay man who is executive producer of the syndicated show, told Frontiers. "She's already shot interviews with the 'cast' of Tyra Banks's trans reality show for VH1, but I want her to do non-LGBT stories. She's delightful."

Watch her interview with Tambor on the following page.

In the clip above, Janet Mock interviews Jeffrey Tambor for Entertainment Tonight.