PTPN1 and astrocytoma (excluding glioblastoma): First, we examined whether the phosphorylation levels of Thr235 of C/EBPß were modulated by PTP1B, in a PAF-dependent context, given that the phosphorylation of this site had been shown to have a role in PGE2-mediated IL-8 modulation in astrocytoma [70].