Late-stage MF, however, is characterized by declining expression of CXCL9 with concomitant increasing expression of T-helper 2 (Th2) associated chemokines such as CCL18. Specifically, studies have revealed elevated CCL18 mRNA levels in MF tumor lesions and serum samples, compared with controls from healthy individuals [65]. This evidence concerns the gene CXCL9 and mycosis fungoides.