Who is the main cast in Seinfeld TV show?

Context: Seinfeld is an American television sitcom created by Larry David and Jerry Seinfeld. It aired on NBC from July 5, 1989, to May 14, 1998, over nine seasons and 180 episodes. It stars Seinfeld as a fictionalized version of himself and focuses on his personal life with three of his friends: best friend George Costanza, former girlfriend Elaine Benes and his neighbor from across the hall, Cosmo Kramer. It is set mostly in an apartment building in Manhattan's Upper West Side in New York City. It has been described as "a show about nothing", often focusing on the minutiae of daily life. Interspersed in earlier episodes are moments of stand-up comedy from the fictional Jerry Seinfeld, frequently using the episode's events for material.

Answer: Jerry Seinfeld
Jason Alexander
Julia Louis-Dreyfus
Michael Richards