It shows that among the 65 predicted ABC transporters, 43 are expressed at least in one of the tested tissues with more than 25 normalized read counts per base. As previously demonstrated in the literature, evaluation of the RNA-seq data with quantitative real-time PCR data shows also in our experiments the comparability of the two methods. Five transcripts were found to be abundant in all tested tissues which suggest their essential role in cellular processes. Among them is, for example,Arctiin CpABC4 which was classified as member of the ABCA subfamily. According to our phylogenetic analysis, the closest human homologs, which are involved in lipid translocation, are clustered into group I of the NBD1 branch. Although the NBD2 of CpABC4 clusters to ABCA12 and 13, the sequence comparison of the complete sequence supported the homology of CpABC4 to human ABCA members of group I. Additionally, CpABC44 an ABCD candidate was highly expressed in all larval tissues, as well. It is homologous to the human ABCD1 and 2 and, therefore, presumably linked to the transport of very long chains of fatty acids in peroxisomes. Furthermore, we detected in all larval tissues abundantly expressed transcripts encoding soluble ABC proteins: CpABC45 as a member of the ABCE and CpABC47 and CpABC48 members of the ABCF subfamily. Also, in the red flour beetle,Naringin dihydrochalcone the Tcabce-3a and Tcabcf-2a transcripts were abundant throughout all life stages and highly abundant in the adult intestinal/excretory tissues and carcass. Furthermore, the silencing of Tcabce-3a as well as Tcabcf-2a resulted in growth arrest and mortality of the beetles. Thus, ABCE and ABCF proteins are essential for cellular functions in all insect tissues including initiation of translation and ribosome biogenesis. In the following, we describe differential expression of putative ABC transporters in the different larval tissues. The existence of ABC transporters in the gut influences the absorption and bioavailability of nutrients, water, ions and plant derived compounds. The predicted ABCA subfamily sequence CpABC5 exhibits a high mRNA level only in the gut tissue. Its deduced protein clusters together with TcABCA-9A/B of T. castaneum.