When does Tracey Takes On... return?

Tracey Takes On... is an American sketch comedy series starring Tracey Ullman. The show ran for four seasons on HBO and was commissioned following the success of the 1993 comedy special Tracey Ullman Takes on New York. The only character to be reprised from the show was Kay Clark.
Tracey Ullman and her cast of characters "take on a different subject" for each episode of the series.