The phrase "are mostly involved in" is correct and usable in written English.
It can be used to describe the primary activities or roles that individuals or groups participate in within a certain context.
Example: "The researchers are mostly involved in studying the effects of climate change on marine life."
Alternatives: "are primarily engaged in" or "are mainly participating in".
Gene Ontology analysis of differentially expressed genes demonstrated that the activated AR program in PC3-AR cells are mostly involved in negative regulation of biological process, which is consistent with the growth inhibition properties of pC3-AR cells observed previously.
The Africans are mostly involved in money laundering.
Several studies have suggested that the miRNAs produced from latent-associated genes are mostly involved in regulating histone-associated enzymes36.
But the numbers are modest, and they are mostly involved in training and organizing arms shipments for a southern insurgency that has yet to take shape or hold.
Transcription factor-binding sites, which are mostly involved in the regulation of immune responses, were predicted at the putative promoter regions of the RbSTAT1 and RbSTAT1L genes.
Secondary metabolites are mostly involved in the relationship of the organism with its environment, e.g. in plant defence mechanisms or as signal compound; their synthesis is often induced by different kinds of biotic and/or abiotic stresses.
In South-east China, the constructed MBRs are mostly involved in the high-strength industrial wastewater treatment while in North China MBRs mainly focused on municipal wastewater treatment and reuse.
Writers at the Scholarly Kitchen blog, who are mostly involved in the less commercial end of publishing, said that although subscriptions for popular titles might be expensive, the cost for each individual reader remained very low.
By contrast, the challengers are mostly involved in retail only.Mr Fitzpatrick, for instance, says he was originally inspired to found Ovo by his "appalling" experience in trying to sort out his bills with his own supplier.
Physicians are mostly involved in decision making on weaning.
Parents are mostly involved in the eldest child's education.
