a, Upper panel, schematic of the SLC45A3-ELK4 chimera located on chromosome 1. Middle panel, qRT-PCR validation of SLC45A3-ELK4 transcript in a panel of cell lines. Inset, histogram of qRT-PCR assessment of the SLC45A3-ELK4 transcript in LNCaP cells treated with R1881. Lower panel, histogram of qRT-PCR validation in a panel of prostate tissues-benign adjacent prostate, localized prostate cancer (PCA) and metastatic prostate cancer (Mets). ETS family gene rearrangement status (by FISH) indicated by horizontal colored bars below graph. Grey not determined (ND); yellow, ETS negative; orange, ETS positive. Horizontal bracket indicates three different metastatic tissues from the same patient (Met4). Asterisk (*) denotes an ETV1 positive sample. b, Chimera classification schema (described in the text).