According to We Got This Covered, Panabaker -- who plays Dr. Caitlin Snow/Killer Frost -- on the series is aiming to leave the show, though a timeline for that departure was not given in the report. Panabaker is reportedly looking to depart in order to pursue other projects, though the website leaves open the possibility that this might be a negotiation tactic. As these rumors are currently unconfirmed, they should definitely be taken with a grain of salt.
Panabaker first appeared as Caitlin in the 19th episode of Arrow Season 2 before joining the main cast of Flash for its 2014 pilot. She has been a series regular since the beginning, and she's quite popular among fans, so many will be sad to see her go. However, as with Valdes, it's possible that her exit might not be permanent.
It's entirely possible that Panabaker's exit will be similar to that of Jeremy Jordan, who played Winn Schott Jr. on Supergirl. Jordan's departed the show so as to appear in the Broadway play American Son. Although it doesn't seem like Jordan will appear in Supergirl Season 4 as was initially planned, he's slated to return in Season 5.
Airing Tuesdays at 8 p.m. ET/PT on The CW, The Flash stars Grant Gustin, Candice Patton, Carlos Valdes, Danielle Panabaker, Tom Cavanaugh, Jesse L. Martin, Danielle Nicolet, Hartley Sawyer and Jessica Parker Kennedy.