For example, reduced growth temperature improves import of catalase, a PTS1 protein, in mammalian cell lines carrying mutations found in several groups of peroxisome biogenesis disorder patients (Fujiwara et al., 2000; Imamura, Tamura, et al., 1998; Imamura, Tsukamoto, et al., 1998). This evidence concerns the gene CAT and peroxisomal disease.