Over the past decade, it has become increasingly apparent that ribosomes are significantly more heterogeneous than originally thought, with variation emanating from both the rRNA and protein content of ribosomes.

This heterogeneity can potentially confer functional ribosome specialization, contributing to translational control, thereby identifying the ribosome as a key regulatory player in translation.

Studies have uncovered interindividual and intertissue variant rRNA alleles and there has also been a recent focus on identifying functional roles for the previously enigmatic eukaryotic rRNA expansion segments.

Technological advances have permitted accurate, quantitative analysis of rRNA modifications across several organisms, with functionality ascribed to certain rRNA modifications.

Other work has centered on identifying specialization arising due to changes in ribosome protein composition.