IFIT1 and myeloproliferative neoplasm: Other upregulated transcripts encode toll-like receptors and their downstream effectors, such as TLR3, TLR5, RIPK2, and IRF7. In addition, some of the most highly upregulated genes in overtly fibrotic MPN included downstream targets of interferon signaling (IFIT1 and MX1; both upregulated 3.5-fold).