For several cancers, the expression of PIWIL1 expression at different stages of cancer has been examined (He et al., 2009; Liu et al., 2010a, 2014; Chen et al., 2015a; Wang H.L. et al., 2015; Sun et al., 2017; Stöhr et al., 2019). This evidence concerns the gene PIWIL1 and cancer.