 a circuit level understanding of immune cells and hematological 
 cancers has been severely impeded by a lack of techniques that enable 
 intracellular perturbation without significantly altering cell viability 
 and function . 
 here , we demonstrate that vertical silicon nanowires 
 ( nws ) enable gene - specific manipulation of diverse murine and human 
 immune cells with negligible toxicity . to illustrate the power of 
 the technique , we then apply nw - mediated gene silencing to investigate 
 the role of the wnt signaling pathway in chronic lymphocytic leukemia 
 ( cll ) . 
 remarkably , cll - b cells from different patients exhibit tremendous 
 heterogeneity in their response to the knockdown of a single gene , lef1 . 
 this functional heterogeneity defines three distinct 
 patient groups not discernible by conventional cll cytogenetic markers 
 and provides a prognostic indicator for patients time to first 
 therapy . 
 analyses of gene expression signatures associated with these 
 functional patient subgroups reveal unique insights into the underlying 
 molecular basis for disease heterogeneity . 
 overall , our findings suggest 
 a functional classification that can potentially guide the selection 
 of patient - specific therapies in cll and highlight the opportunities 
 for nanotechnology to drive biological inquiry . 
Supplementary Material