In order to remove the border of a UITableViewCell, set it’s background view to the following:
UITableCiewCell *topCell = [self.tableView cellForRowAtIndexPath: [NSIndexPath indexPathForItem:0 inSection:0]];
topcell.backgroundView = [[UIView alloc] initWithFrame:CGRectZero];
It took me a little while to find this answer, so I thought I’d post it just in case anybody else needed it.