Expression of α6A and α6B integrin subunits in colon cancer specimens. Representative images by indirect immunofluorescence staining of α6A (A, C, E and G) and α6B (B, D, F and H) integrin subunits in serial sections of colon cancer specimens (A, B; C, D; E, F and G, H) showing the loss of variant segregation, leading to widespread overlap of both variants (arrows). Some regions, however, displayed the expression of only one variant, with no expression of the other (arrowheads). Red-brown signal: Evan's blue counter stain. Magnifications: scale bars = 50 μm.