Both are about a strong righteous female characters and their of fighting battles related to work while protecting everyone else. Both actresses are one of the best Kim Hye Soo & Lee Yo Won. Both dramas carry on strong message about work and life and gives importance to the supporting characters as well. Both dramas handle the comedy aspect very well and in both dramas the romance isn't essential but you can still feel it and it's represented in a very mature manner. Highly recommended.

Kim Eun Hee is the genius writer who wrote Signal and she is also the one who wrote Sign. Sign is also one of the best crime thriller dramas out there. If you are looking for something as good as Signal then you should definitely watch Sign and vice versa. Both dramas are blessed with excellent unforgettable plot, perfectly written characters and TOP actors. Sign has Park Shin Yang as the main lead and he is one of the best top notch actors. Both dramas gained high TV ratings and a must watch dramas.