_Follow along with this video:_ --- The next time you search your `@Audit` tag, you may come across a note I briefly mentioned on an MEV vulnerability in Puppy Raffle's `refund` function. ```js function refund(uint256 playerIndex) public { // @Audit: MEV address playerAddress = players[playerIndex]; require(playerAddress == msg.sender, "PuppyRaffle: Only the player can refund"); require(playerAddress != address(0), "PuppyRaffle: Player already refunded, or is not active"); // slither-disable-next-line reentrancy-no-eth,reentrancy-events payable(msg.sender).sendValue(entranceFee); players[playerIndex] = address(0); emit RaffleRefunded(playerAddress); } ``` We're actually going to skip this one for now. MEV's are something we'll return to later in the course to gain a deeper understanding of how they work. For now, just mark this note as skipped and we'll continue to the next vulnerability.