PI3 and psoriasis: The expression of psoriasis-related host defence genes PI3 and DEFB433–35 (encoding SKALP/elafin and hBD2, respectively) was increased in both primary and N/TERT keratinocytes, but N/TERT keratinocytes showed a significantly stronger upregulation and this was most pronounced in N/TERT2G cultures (Fig. 3B).