Periostin is known to induce expression of thymic stromal lymphopoietin (TSLP) from keratinocytes and both periostin and TSLP are elevated in CTCL skin lesions and serum when compared with skin and serum from healthy control subjects (Miyagaki et al., 2009; Tuzova et al., 2015; Takahashi et al., 2016). This evidence concerns the gene TSLP and primary cutaneous T-cell non-Hodgkin lymphoma.