Microenvironmental adhesive interactions may be involved in gene regulation in malignant B-cells. The figure shows the different gene expression profiles of Type-A (highly adhesive), Type-F (poorly adhesive), and AF (Type-A cells devoided of adhesion) variant malignant B-cells, all originated from the same clone. The groups of genes identified include the following: primary (intrinsic; adhesion-independent) differences; secondary (adhesion-dependent) differences; and secondary (detachment-induced) differences in gene expression between the variant cells. As shown, the expression levels of most genes increase in the adhesive population, in an adhesion-independent (primary) or adhesion-dependent (secondary) manner. The analysis uncovered the relative contribution of adhesive interactions to fibronectin, to the gene expression profile of malignant B-cells. For details, see article by Nadav-Dagan and colleagues on page 482 in this issue.