Aspects of the invention provide single stranded oligonucleotides for activating or enhancing expression of ATP2A2. Further aspects provide compositions and kits comprising single stranded oligonucleotides for activating or enhancing expression of ATP2A2. Methods for modulating expression of ATP2A2 using the single stranded oligonucleotides are also provided. Further aspects of the invention provide methods for selecting a candidate oligonucleotide for activating or enhancing expression of ATP2A2.