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Bonnie Franklin -- star of the long-running '70s-'80s sitcom One Day at a Time -- has been diagnosed with pancreatic cancer.

A family spokesman told ET in a statement on Monday: "Actress Bonnie Franklin has been diagnosed with Pancreatic Cancer and is currently undergoing treatment." The statement adds that the star is "continuing with her normal schedule." 

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"She and her family remain extremely positive and thank everyone for their support and concern. Respect for her privacy is greatly appreciated," the statement said. 

One Day at a Time starred Franklin as a divorced mother bringing up her two teenage daughters -- played by Valerie Bertinelli and Mackenzie Phillips. After hearing the news, Phillips tweeted a message of support. "Sending out love and sweet prayers to my 'mom'. The incomparable Bonnie Franklin."

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