Properties of vlincRNA-associated promoters. VlincRNAs tend to have promoters at one of their bounds (A, B) belonging to either the Active or All category of promoters. This tendency was common to all vlincRNAs (A) or the stand alone vlincRNAs (B) defined based on being at least 50 kb away from the nearest gene on either side. Panels A and B show the density of ENCODE promoter coverage (Y-axis) in all 9 ENCODE cell lines (see text) summed up in 1 kb bins +/-50 kb around boundary of each vlincRNA of the 2,147 vlincRNA (see Additional File 1, Table S1). The coordinates on the X-axis refer to middle position of each bin. VlincRNAs assigned to LTR-containing promoters from any of the 9 cell lines tend to be more tissue specific (C) and have a higher RNAseq signal (D).