However, we exclude this hypothesis for two reasons.
However whereas EN is expressed in the glia [16] [48], we found that GsbN was not expressed in the glia (Figure S2), which also excludes this hypothesis.
In that study we did not find an association between C677T MTHFR polymorphism per se and NVAF [9], but those results were not conclusive, because the number of patients examined was not sufficient to definitively exclude this hypothesis.
To exclude this hypothesis, our study is still ongoing and we intend to widen the study cohort.
However, we did not observe any alternative transcripts after the transition from monoallelic to biallelic expression, thus excluding this hypothesis (data not shown).
Although we cannot exclude this hypothesis, other interventions such as administration of macrophage-colony stimulating factor, in a similar time frame than in the present study, was able to aggravate elastase-induced emphysema [ 53].
Although we think that an inland reintroduction of the infection is unlikely to occur for 4 consecutive years under the same pattern, we cannot exclude this hypothesis until molecular analysis of the isolates is available.
While this provides no support for the hypothesis that K- ras 4A plays a role in modulating intestinal tumorigenesis, it does not exclude this hypothesis, which is worthy of further examination given the high expression levels and established pro-apoptotic action of K- ras 4A in mouse intestine and the antagonistic effects of the 4A and 4B isoforms [ 16].
We cannot formally exclude this hypothesis with the data at hand, but it could be tested if genetic markers linked to the autosomal gene segregating in the earlier studies (11, 14) and sex-linked markers linked to the resp locus were both followed in the same set of crosses.
Thorough control experiments would need to be added to exclude this hypothesis: A quantification of what percentage of the cell death events reported upon apoptosis-inducing treatments in Figures. 2 and 3 results from live extrusion (similar to the quantification on Figure 4D) would be required to fully understand the results reported.
