The aneuploidic increases in copy number of genes that may promote tumor formation, including ARHGAP26, GRB10, DDHD2, FGFR1, CTNNA3, PTPN1 and MLLT1 in the apparently stable and karyotypically normal lines HS293 and HS401, are cause for concern. This evidence concerns the gene ARHGAP26 and neoplasm.