Lena Dunham made the emotional discovery that her family has connections to the Holocaust during last week’s episode of the PBS celebrity genealogy series Finding Your Roots.

Historian and host Henry Louis Gates Jr. revealed that Dunham’s great-great-grandmother Regina Seltenwirth came to the US alone at just 14 years old, leaving 11 siblings behind in Europe. Gates explained that one of Regina’s brothers, Moses, moved with his family to Hungary around the time that WWII began; the family was separated, and his daughter Ilona was sent to the Nazi-occupied city of Kamianets-Podilskyi where she is believed to have been one of roughly 24,000 Jews who were massacred over the course of two days in August 1941.

“It’s an incredibly painful thing to think about people with whom I share probably not just DNA but, you know, features and emotional responses and an approach to life – those people being placed in this situation and having their lives extinguished this way,” Dunham said. “I don’t think there is a way to reckon with it. It’s too big and the whole act is too vast. But to see a personal connection to it literalises it in a way that is very, very powerful.”

Dunham, 37, whose mother is Jewish, stars in the upcoming film Treasure in which she plays a young woman confronting her family’s Holocaust history, and her discovery on Finding Your Roots proved the Jewish actor and writer of the hit HBO series Girls has more in common with her character than she’d previously known.

Gates went on to explain that the names of Moses, his wife and their son later appeared on a list of living Hungarian Jews compiled by Allied soldiers at the end of the war, and Ilona's name was notably missing.

“It’s an amazing thing to see those names, and to know that they’re a part of our family,” Dunham said. “But to also know that they had to spend the rest of their lives with this other person — who was so important to them — missing, and wondering about her fate, must have made surviving a very complicated thing.”

Dunham, who appeared on last Tuesday’s episode alongside Jewish actor Michael Douglas, also learned that she is a distant relative of Curb Your Enthusiasm star Larry David. Gates explained that David is a cousin through Dunham’s mother, Laurie Simmons. According to the show’s DNA analysis, David shares “multiple long identical segments of DNA” with Dunham and her mother.

“This means that you share at least one common ancestor somewhere on your mother's side of your family tree,” Gates added.

Dunham was “delighted” by the news: “This is incredible. You saved the best for last.”

Finding Your Roots has featured a number of Jewish celebrities who explored previously unknown Jewish family histories, including Alanis Morissette, Pamela Adlon, David Duchovny, Dustin Hoffman and others.