Is it possible to attach UITapGestureRecognizer to UILabel subclass

I'm trying to attach gesture recognizer to my own class which is subclass of UILabel, but it does not work. Can you help me to understand what's wrong in the code

 
@interface Card : UILabel  {

}

- (void) addBackSideWord;

@end

#import "Card.h"

@implementation Card
- (id)initWithFrame:(CGRect)frame {

    if ((self = [super initWithFrame:frame])) {

        UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
                         initWithTarget:self action:@selector(addBackSideWord)];
        [tapRecognizer setNumberOfTouchesRequired:2];
        [tapRecognizer setDelegate:self];
        [self addGestureRecognizer:tapRecognizer];
    }

    return self;
}

- (void) addBackSideWord {

     //do something
}
@end