ERBB2 and neoplasm: All aRMS tumor cell suspensions displayed low but homogenous ERBB2 expression (RH30, MFI 3.6 ± 0.0, n = 3; RH41, MFI 1.7 ± 0.1, n = 3; primary aRMS cells, MFI 1.9, n = 1) (Figure 2D).