PTGDR and breast cancer: In breast cancer, miR-3156-5p has been reported to target the proapoptotic gene, Caspase 2 (CASP2) and the long ncRNA tumour protein translationally controlled 1 (TPT1) antisense RNA 1(TPT1-AS1), thereby facilitating TPT1-AS1 inhibition of cell proliferation and sensitisation of breast cancer cells to chemotherapy (Huang et al. 2021).