Samantha Ronson hit The Roosevelt in Hollywood Tuesday night to support the launch of her sister Charlotte's I "Heart" Ronson line at JCPenney's.

Ronson DJ-ed at the party, presented by Svedka Clementine Vodka, which was attended by Zac Efron, Nicole Richie, Paris and Nicky Hilton, Ashlee Simpson, Jordana Brewster, Alice Eve and Danny Masterson.

Of course, Ronson's ex Lindsay Lohan could not attend since she's currently under court-mandated house arrest.

Check out a pic of Samantha DJ-ing at the event after the jump, and see Zac Efron in our gallery below. He made quite the exit!