Grable's success as a pin-up girl furthered her career as a mainstream movie star. As her star continued to ascend, Fox chief Darryl F. Zanuck expressed interest in broadening Grable's range as an actress. Zanuck attempted, on multiple occasions, to cast her in films that challenged her acting abilities, but Grable was reluctant; she felt insecure about her talent which rendered her unwilling to accept roles she felt required too much of her. Throughout her career, she was very cautious; she often worried about starring opposite well-known leading men. She preferred to star in up-beat and outlandish musicals, many of which followed the generic boy-meets-girl story tack. In fact, many of her movies were thin when it came to their stories, but they were high on energy during their song-and-dance sequences. Despite their lack of quality, Grable's movies were immensely popular, and Fox regularly channeled the profits it received from Grable's movies into their more prestigious movies.