Localization of TIL3 and TIL4 to human chromosome regions 1q41-q42 and 4q31.3-q32, respectively, by FISH. (A) TIL3. Summary of the locations of hybridization signals observed among 10 mitotic cells hybridized with plasmid TX667U3288L. Signals were observed in the 1q41-q42 region on both homologs (black circles) of 6 cells and only a single homolog (gray circles) in 4 cells, for an overall efficiency of 80%. Signals were not observed consistently at any other location. (B) TIL4. Summary of the locations of FISH signals observed among 10 mitotic cells hybridized with BAC 21K16, which contains TIL4. Hybridization signals were observed at 4q31.3-q32 on both homologs in each cell.