Representative examples of 4q13.3 and 13q14.2 aberrations by cIg-FISH. The clonal PCs in all cases are identified by cytoplasmic immunofluorescence staining of κ light chain (green, FITC) or λ light chain (red, PE). The images in the left column are MGUS cases (n = 5) while those in the right column are MM cases (n = 5). Yellow arrows indicate signals by the 4q13.3 region-specific probe (yellow); red arrows, signals by the 13q14.3 region-specific probe (red); and green arrows, signals by the chromosome 10 centromeric reference probe (green). (A) Four representative cases with copy number loss in 4q13.3 (1 yellow) but not 13q14.2 (2 red). (B) Two representative cases with copy number loss in 13q14.2 (1 red) but not 4q13.3 (2 yellow). (C) Four representative cases with copy number losses in both 4q13.3 (1 yellow) and 13q14.2 (1 red). Images were visualized using a Zeiss Axioplan 2 fluorescence microscope equipped with a charge-coupled device camera and a 40×/0.75 numerical aperture oil objective lens. Images were processed using ISIS3 software (MetaSystems).