JAK2 and melanoma: Similar conclusions have been reached using in vivo CRISPR-Cas9 library screening studies showing that sgRNAs targeting Jak1/Jak2 and Stat1 as well as interferon receptors were significantly enriched in murine melanoma B16 cells placed in immune-competent, syngeneic C57B/L mice, compared to the same cells (with the same sgRNA library pool) grafted in immunodeficient mice18,19.