(a) Above: percentages of cells that accumulate MBds (>1) in a range of different cell types, as indicated. Below: doubling times of representative cell lines aligned with MBd-accumulation data. Data are presented as mean±s.d.; cell lines are examined in triplicate (MCF-10A, DLD-1, MCF-10AT, MCF-7, H1 and H9) or quadruplicate (e.v. B6 MEFs, HeLa, SAOS-2 and MCF-10CA1a), except hRPE-1 (n=6), U2OS (n=7) and NCC-IT (n=8). Horizontal line, cell lines with different MBd accumulation potentials (14-fold) but similar doubling times. 