between tumorigenicity and tumor volume in NSG and B6 hosts could suggest that D4M cell lines are relatively
non- immunogenic, like murine B16 cells (Ashley and Kotlarski, 1986; Leveson et al., 1979). This is consistent with the expression of low levels of MDAs in culture and the relative paucity of immune cells in the tumor tissue (as seen by histology; data not shown).