Abstract: The invention relates to inhibitors of Sghrt and/or Gas5 lincRNAs, in particular to polynucleotides complementary to coding and non-coding sequences of said lincRNAs, and methods of producing said inhibitors. Also disclosed are the use of the afore agents to proliferate, regenerate or dedifferentiate a heart cell; methods for preventing and treating cardiac disease using the afore agents; and a prognostic or diagnostic assay to assess the regenerative or proliferative capacity of heart tissue before, after or during a cardiac treatment regimen, comprising determining the presence or amount of Sghrt and/or Gas5 lincRNAs. The present disclosure also relates to a method for screening for a therapeutic agent that can be used to treat or prevent a heart disorder, comprising analysing the functional expression and/or expression level of Sghrt and/or Gas5 lincRNAs in the presence and in the absence of the therapeutic agent.