The selected variants XPC 1496C>T, XPC 2920A>C, XPD 2251A>C, XPF-673C>T, XPF 11985A>G, and XPG 3507G>C were studied in different populations for multiple types of cancers: breast cancer [19,20], bladder cancer [18,21,22,23], ovarian cancer [28], hematological diseases such as Hodgkin’s Lymphoma [24,25], PV and ET [26], AML [29], and CML [32,33]. This evidence concerns the gene ERCC5 and essential thrombocythemia.