CASC9 and gastric cancer: Several lncRNAs, such as bladder cancer-associated transcript 1 (BLACAT1), MRUL, PVT1, and CASC9, have been reported to regulate the development of MDR in GC by directly or indirectly targeting MDR1. For instance, Xu et al. found that lncRNA BLACAT1 was upregulated in OXA-resistant GC tissues and cell lines and that its overexpression promoted the OXA resistance of these GC cells by upregulating MDR1 expression via sequestering miR-361 (72).