The VIT-vWFA domain arrangement of Vwa1 is characteristic of a broad protein family that includes extracellular ITIH heavy chains (Himmelfarb et al., 2004; Zhuo et al., 2004), a specific intracellular poly ADP-ribose polymerase (PARP4) (Perina et al., 2014), and the intracellular tumor suppressing VWA5A/BCSC-1 (Martin et al., 2003; Anghel et al., 2012; Di et al., 2018). This evidence concerns the gene VWA5A and neoplasm.