Clojure: remove from list

Source: How can I remove specific element from a list?
Tip: use a set.

;; Remove elements:
(remove #{3 5} [1 2 3 4 5 6 7 8 9])

;; Keep elements:
(keep #{7 5 3} [1 2 3 4 5 6 7 8 9])

;; Check if element exists:
(some #{5} [1 2 3 4 5 6 7 8 9])