A member of the Janus kinase family, JAK2 is involved in different cell signaling reactions [49], and this interaction with other proteins, such as STAT and PI3K, may cause cell death or tumor formation [50,51], mediate MMP proteins [33], and enhance PD-L1 regulation, which has been proven to have a role in tumor metastasis and immune escape [52]. The gene discussed is JAK2; the disease is neoplasm.