The first factor is not the case for the present study, because we did not use the calibration dates based on previous molecular studies, but used only those based on fossil records.
Equally, on molecular biological studies, only a small part of the tumour is analysed and molecular differences may well exist within different regions of the same tumour as well as between different patients' tumours.
Previous molecular studies sampled only one or a few individuals of different populations, focusing largely on allozymes [ 26] or mtDNA [ 23].
Our molecular study showed only the genotypes of the drug resistance genes; further in vitro and in vivo studies are required to corroborate these findings.
The only molecular studies of wood formation in Japanese cedar have identified large numbers of genes that are expressed in male strobili [ 21].
As most of the other molecular studies in thyroid nodules included only KRAS codon 12/13 but not codon 61 [ 24, 28, 29], it is difficult to compare our result to the others.
Previous studies on the host were only targeted molecular studies and no global molecular analysis has been carried out on the host Riftia pachyptila to date.
The large-eared tenrec (G. aurita) has been included until now in only two molecular studies, by Olson and Goodman [ 17] and by Asher and Hofreiter [ 18].
So far, only three molecular studies have investigated hybridization between closely related odonate species, namely between Coenagrion puella and C. pulchellum [ 14], Mnais costalis and M. pruinosa [ 15, 16] and Calopteryx splendens and C. virgo [ 17].
In a recent review by van de Wijgert and colleagues, only three molecular studies reported vaginal microbiome clusters dominated by streptococci, staphylococci, and/or E. coli [ 43, 57, 58].
