Unlike true big cats of subfamily Pantherinae, the cheetah can purr as it inhales, but cannot roar. By contrast, the big cats can roar but cannot purr, except while exhaling. The cheetah is still considered by some to be the smallest of the big cats. While it is often mistaken for the leopard, the cheetah does have distinguishing features, such as the aforementioned long tear marks that run from the corners of its eyes to its mouth, and spots that are not "rosettes". The thinner body frame of the cheetah is also very different from that of the leopard.