Polyadenylation and the formation of a transcript 3’ end are important steps for the maturation of newly transcribed mRNAs. These processes, which have a direct effect on the stability, localization and even the translation of mRNAs, depend on the function of the gene terminator. However, this is not the only way terminators can affect gene expression. The use of different terminators can result in dramatic changes in the levels of transgene expression, and as we previously showed, lead to the generation of small RNAs (sRNAs) and transgene self-silencing. How different terminators can have such an effect on gene expression is still poorly understood. It most likely involves the presence of aberrant transcripts originating from read-through transcription as the result of poor transcription termination and it is usually linked to terminators showing low efficiency combined with strong transcriptional levels. We identified in the terminator of several Arabidopsis genes a sequence essential for keeping the levels of read-through transcription and sRNAs to a minimum. For this reason, we named this new element the “Read-Through and Silencing Suppressor” (RTSS) domain. We are currently investigating how widespread and conserved this element is in different plant genomes and studying the significance of the RTSS domain for the expression of endogenous plant genes and their protection against self-silencing caused by transcription-associated sRNAs.