Immunofluorescence microscopy of patient and control fibroblasts; ACG1A_1 carries the homozygous LBR mutation described in this study, ACG1A_2 and 3 bear biallelic mutations of TRIP11; CTL_1 and 3 are representative matched wild-type controls. Cells were grown on coverslips, fixed, and costained with (A) LBR- and lamin B–specific antibodies, or (B) using antibodies directed against GMAP-210 and the cis-Golgi marker GM130. Nuclear DNA was stained with Hoechst 33342 dye. White lines indicate where red, green, and blue (RGB) fluorescence was quantified; RGB profile plots of the sections are shown on the right. Scale bars: 10 μm.