Target RNA-directed microRNA degradation; which controls which?

In general, microRNAs (miRNAs) control target gene expression by inhibiting translation and destroying target RNAs (1,2). However, interestingly some endogenous coding or noncoding RNAs have a function to sequester miRNAs from the real target RNAs by hybridization (called sponge function) without degradation and they are also known as competing endogenous RNAs (ceRNAs) (3,4).