Blue Bloods got viewers invested in the Reagan family — but how are the characters related to each other? The CBS series, which premiered in 2010, followed the lives of the Reagan family, many of whom worked for the NYPD under the leadership of NYC police commissioner Frank Reagan (Tom Selleck).

CBS’s upcoming “Blue Bloods” spinoff has recast Danny Reagan’s son after the same actor played the recurring role throughout the original 14 seasons. Andrew Terraciano will not return as Sean Reagan in “Boston Blue” after appearing in nearly every episode across 14 seasons as the son of Donnie Wahlberg’s character,