PTGDR and melanoma: Taken the above results together, the findings revealed that PTBP1 promoted the splicing of LHFPL3-AS1 precursor to generate LHFPL3-AS1-long, and subsequently LHFPL3-AS1-long inhibited the mRNA degradation of Bcl-2 (the target gene of miR-181) by its direct interaction with miR-181a-5p to suppress apoptosis of melanoma stem cells, thus leading to tumorigenesis of melanoma stem cells in vivo (Fig. 7L).