JAK2 and Rare hereditary thrombophilia: Finally, there are several conditions that are not specifically associated with CD, but, if present, could predispose that individual to a TE, for example, some cases of inherited thrombophilia (PT20210, FV Leiden), malignancies (myeloproliferative neoplasms—JAK2 mutation), pregnancy, immobilization, or the use of contraceptive pills.