The results from the two studies are not directly comparable, owing to a number of major methodological differences, including different measurement protocols and fundamentally different paradigms.
In a systematic review of six microarrays studies, it was suggested that the low consensus for differential gene expression in cSCC resulted from clinical and methodological differences, including small sample sizes, tissue processing, different baseline comparators (normal skin or AK) and varied bioinformatic approaches (Van Haren et al, 2009).
Alternatively, they may be due to methodological differences, including study design and response/relapse definitions.
Cross-lagged panel models overcome many previous limitations; however, findings from the few studies employing these designs have been mixed, possibly due to methodological differences including self-report versus clinician-administered assessment.
Numerous other possible explanations stem from methodological differences including choice of cell type, the levels of MYC overexpression, time of overexpression, and the choice of MYC family member as the exogenous transgene.
Though both the hotplate and tail-flick involve thermal nociception, this difference may be related to methodological differences including rat strain, body part tested, diet composition, stimulus strength (latencies are generally longer in our study), and length of dietary treatment (12 wk in Ziegler et al).
Methodological differences included Lad's comparison of all minorities to Whites, whereas we compared all other races to the AI/AN population.
Other methodological differences exist, including different mass spectrometry protocols (different columns for separation) and different fly strains (w 1118 vs. Canton S).
These discrepancies could be explained by methodological and preservation differences, including the post-mortem fixation delay which could contribute to antigen masking and in consequence a misevaluation of the proliferation rates [44].
The different outcomes between studies likely reflect methodological differences, potentially including that we did not specifically manipulate FoxP2.
In view of the differences, including methodological, ancestral and cultural, across populations, caution should be taken when comparing results from multiple studies.
