Variation in the rigidity of initial copy number in different chr3 segments. A. Chr3 ideogram with the localization of FER and CRR regions (empty horizontal bars through the figure). B-C. Analysis of the genetic material of the expanded clones shows that elimination of the "lost chr3 segments" in contrast to the "retained chr3 segments" was associated with growth advantage (see figures 3 and 4). Therefore we compare these "lost chr3 segments" (red vertical bars) with the "retained chr3 segments" (green vertical bars) in order to find a "mandatory copy number region. MpFISH identified chr3 regions that are present on the "lost" (red) and the "retained segments" (green) in KH39 and Hone1 derived MCHs (see figures 3 and 4) (gray: the region was not analyzed). D. Summary of data concerning the regions involved in growth suppression following chr3 transfer into tumor cell lines, as reported at the time of publication. Note that many of the early MMCT studies were limited by availability of genetic markers for assaying content of hybrids or were not performed comprehensively to include genetic marker analysis of both chromosome arms. Red: reported regions associated with the growth suppression: (1) in ovarian carcinoma line HEY . (2) in breast carcinoma line 21NT ; (3) in RCC cell line RCC23 ; (4) in RCC cell line KC12 ; (5) and (6) in mouse fibrosarcoma A9 cell line  and ; (7) in NPC Hone1 cell line ; (8) in esophageal squamous cell carcinoma cell line SLMT-1 . Green: common retained region (CRR) tends to persist in mouse fibrosarcoma A9/human chr3 MCHs after 4 consecutive passages through SCID mice. (9) ; (10) the region was reduced to the segment between PCR markers D3S1282 (3q26.2) and D3S1262 (3q27.3) (our unpublished data). E. Data about losses and gains of chr3 segments in 510 cases of colorectal, renal, parathyroid, lung, pancreas, breast, cervical, fallopian tube, ovarian, vaginal and tonsil carcinomas reported in NCBI SKY/M-FISH and CGH Database . Each red line corresponds to the loss, each green – to the gain of the segment in a particular tumor sample.