It has been shown that host cells regulate L1 retrotransposition activity, for example through epigenetic silencing.
For example, the RNA interference (RNAi) mechanism of small interfering RNAs derived from L1 sequences can cause suppression of L1 retrotransposition.
In plant genomes, epigenetic modification of LINEs can lead to expression changes of nearby genes and even to phenotypic changes: In the oil palm genome, methylation of a Karma-type LINE underlies the somaclonal, mantled variant of this plant, responsible for drastic yield loss.
Human APOBEC3C mediated restriction of LINE-1 elements were reported and it is due to the interaction between A3C with the ORF1p that affects the reverse transcriptase activity.