Uncle Jessie says he used to be an ER doctor in another life. John Stamos played an ER doctor on ER (1994).
Lori Loughlin was not invited back to the show after Season 4, which was due to her criminal indictment involving college bribery. The non-appearance of her character is explained here because Aunt Becky is visiting her mother in Nebraska.
Josh Peck, who plays Ben, starred with John Stamos in the show Grandfathered.