The Down syndrome cell adhesion molecule antisense RNA 1 (DSCAM-AS1) is an intronic antisense lncRNA that is transcribed from the opposite strand of the Down syndrome cell adhesion molecule (DSCAM) gene, and is wholly derived from the intronic region of DSCAM. DSCAM-AS1 promotes tamoxifen resistance [110,111] and is upregulated in breast cancer tissues compared with normal tissues [110,112]. Here, DSCAM-AS1 is linked to breast cancer.