For example, the lncRNAs LOC100128593 and PGM5-AS1 showed the most pervasive down-regulation in 13 cancer types; several well-characterized lncRNAs such as HOTAIR [32, 36], H19 [37–39] and PVT1 [16, 40, 41], also showed dysregulation in at least nine different cancer types. Here, PTGDR is linked to cancer.