In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Q: Context: The blasticidin S resistance gene (bsr) is a selectable marker used for gene transfer experiments. The bsr gene encodes for blasticidin S (BS) deaminase, which has a specific activity upon BS. Therefore, its expression is supposed to be harmless in cells. The work reported on herein consisted of experiments to verify a possible toxicity of bsr on mammalian cells, which include several cell lines and primary cultures.', 'Murine keratinocyte BALB/MK and human primary keratinocyte cells transduced with the retroviral vector LBmSN, which has an improved expression system of bsr, namely bsrm, died in five days after the transduction. Meanwhile the control vector LBSN, which expresses bsr, did not provoke cell death. The lethal activity of bsrm was observed only in human keratinocytes and BALB/MK cells among the cell types tested here. Death appears to be mediated by a factor, which is secreted by the BALB/MK transduced cells.\Question: Is over expression of the selectable marker blasticidin S deaminase gene toxic to human keratinocytes and murine BALB/MK cells?

A: By our study we demonstrated that the expression of bsrm gene is toxic to human keratinocytes and BALB/MK cells. It is likely over expression of BS deaminase gene is responsible for the death.
****
Q: Context: The CARD14 gene encodes a protein that enhances nuclear factor (NF)-κB activation and the upregulation of proinflammatory pathway genes. CARD14 is upregulated in psoriatic vs. normal skin, and rare and common CARD14 variants have been associated with the risk of developing psoriasis. Our hypothesis was that CARD14 variants could also influence the response to antitumour necrosis factor (anti-TNF) therapies among patients with psoriasis.', 'To determine whether CARD14 gene variants were linked to a significant positive anti-TNF response in patients with psoriasis.', 'DNA from 116 patients with psoriasis was subjected to next-generation sequencing of the CARD14 gene. All of the patients were nonresponders or had contraindications to conventional systemic treatments.', 'A reduction of at least 75% in Psoriasis Area and Severity Index (PASI 75) at week 24 was considered a positive response to treatment. In total 116 patients (79 responders and 37 nonresponders) were next-generation sequenced, and we identified five nucleotide variants that would result in missense amino acid changes. These variants were determined in all of the patients, and allele and genotype frequencies were compared between the two groups. We found a significantly higher frequency of rs11652075 CC (p.Arg820Trp) among the group with a positive response (P = 0.01, odds ratio 3.71, 95% confidence interval 1.30-10.51). Furthermore, among responders, six patients were heterozygous carriers of the rare p.Glu422Lys variant, and two patients were heterozygous for p.Arg682Trp (P = 0.04).\Question: Do common and rare CARD14 gene variants affect the antitumour necrosis factor response among patients with psoriasis?

A: The common CARD14 p.Arg820Trp variant might have a significant effect on the response to anti-TNF therapies among patients with psoriasis. In addition, rare CARD14 missense variants could also predispose to a better response.
****
Q: Context: To determine the extent of genetic variation among internationally collected HIV-1 isolates, to analyse phylogenetic relationships and the geographic distribution of different variants.', 'Phylogenetic comparison of 70 HIV-1 isolates collected in 15 countries on four continents.', 'To sequence the complete gag genome of HIV-1 isolates, build multiple sequence alignments and construct phylogenetic trees using distance matrix methods and maximum parsimony algorithms.', 'Phylogenetic tree analysis identified seven distinct genotypes. The seven genotypes were evident by both distance matrix methods and maximum parsimony analysis, and were strongly supported by bootstrap resampling of the data. The intra-genotypic gag distances averaged 7%, whereas the inter-genotypic distances averaged 14%. The geographic distribution of variants was complex. Some genotypes have apparently migrated to several continents and many areas harbor a mixture of genotypes. Related variants may cluster in certain areas, particularly isolates from a single city collected over a short time.\Question: Does phylogenetic analysis of gag genes from 70 international HIV-1 isolates provide evidence for multiple genotypes?

A:
The genetic variation among HIV-1 isolates is more extensive than previously appreciated. At least seven distinct HIV-1 genotypes can be identified. Diversification, migration and establishment of local, temporal 'blooms' of particular variants may all occur concomitantly.
****