Main BJ, et al. - In view of the importance of tissue-specificity in gene expression assays and active expression of the candidate P450 gene CYP9K1 in Malpighian tubules, researchers used RNA-seq to determine expression differences between alternative haplotypes at CYP9K1 (cyp-1 and cyp-2) in Malpighian tubules in the following mosquito strains from Mali: 1995 An. coluzzii (MOPTI; MRA-763), 2014 An. coluzzii (Selenkenyi), and An. gambiae (pimperena; MRA-861). They noted significant P450-related insecticide resistance in the 2014 An. coluzzii colony, indicating that insecticide-treated bed nets (ITNs) treated with the P450 inhibitor piperonyl butoxide (PBO) would be more effective in this region. The known insecticide resistance gene CYP6Z1 was observed to be differentially expressed exclusively in the context of sublethal permethrin exposure, emphasizing the significance of tissue-specificity and environmental conditions in gene expression studies. Resistance to other insecticides like organophosphates was suggested by the increased activity of the carboxylesterase COEAE5G in the resistant An. coluzzii colony.