What is one of the functions of retinoids beyond regulating cell growth?

Retinoids, which are derivatives of vitamin A, play a crucial role in various physiological functions within the human body. One of their most important functions is their role in vision. Specifically, retinoids are vital for the formation of rhodopsin, a pigment found in the retina that is essential for the perception of light and color. Rhodopsin absorbs light and enables the photoreceptor cells in the eyes to send signals to the brain regarding visual images. This function is particularly critical for night vision, as it allows individuals to see in low-light conditions.

In addition to vision, retinoids are involved in other metabolic processes, such as regulating gene expression and influencing immune function, but their relationship with vision is a foundational aspect of their biological significance. This clearly highlights why the option focusing on their role in vision is the correct answer, as it underscores an essential and well-established function of retinoids in human physiology.