Fcilitated diffusuin is sensitive to inhibitors as well as show saturation effect?............pls explain this sentence .......

Facilitated diffusion is mediated by carriers which are proteins. Any inhibitor which is capable of altering the sensitivity of this carrier either by distorting physical shape or chemical affinity can limit the diffusion process. Also saturation i.e. accumulation of chemicals on one side may limit the process due to skewed concentration gradient.