A number of breeders produce small-stature Persian cats under a variety of names. The generic terms are ''Toy'' and ''Teacup'' Persians (terms borrowed from the dog fancy), but the individual lines are often called ''palm-sized'', ''pocket'', ''mini'' and ''pixie'', due to their relatively small size. Currently, they are not recognized as a separate breed by major registries and each breeder sets their own standards for size. These terms are considered controversial or marketing ploys as cats do not have the genetic mutations that dogs possess to produce miniature versions of themselves as cats have a strong genetic buffering mechanism that keeps the genes from mutating. Unscrupulous breeders have resorted to harmful and repetitive inbreeding to obtain smaller cats, resulting in genetically weaker cats often with severe health issues and shortened lifespans.