Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Let me give you an example: Context: Architecturally, the school has a Catholic character. Atop the Main Building's gold dome is a golden statue of the Virgin Mary. Immediately in front of the Main Building and facing it, is a copper statue of Christ with arms upraised with the legend 'Venite Ad Me Omnes'. Next to the Main Building is the Basilica of the Sacred Heart. Immediately behind the basilica is the Grotto, a Marian place of prayer and reflection. It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858. At the end of the main drive (and in a direct line that connects through 3 statues and the Gold Dome), is a simple, modern stone statue of Mary.
Question: To whom did the Virgin Mary allegedly appear in 1858 in Lourdes France?
The answer to this example can be: Saint Bernadette Soubirous
Here is why: This is the correct answer. Because the question is asking for the name of the person and following sentence from the passage answers it: It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858.

OK. solve this:
Context: The objective of this study was to analyze the expression levels of multiple components in the mammalian target of rapamycin (mTOR) signaling pathway in radical nephrectomy specimens from patients with metastatic renal-cell carcinoma (RCC) treated with mTOR inhibitors in order to identify factors predicting susceptibility to these agents. This study retrospectively included a total of 48 consecutive patients undergoing radical nephrectomy, who were diagnosed with metastatic RCC and subsequently treated with an mTOR inhibitor (everolimus or temsirolimus) as either first- or second-line systemic therapy. Expression levels of 5 molecular markers involved in the signaling pathway associated with mTOR, including PTEN, phosphorylated (p)-Akt, p-mTOR, p-p70 ribosomal S6 kinase, and p-4E-binding protein 1 (4E-BP1), were measured by immunohistochemical staining of primary RCC specimens. Of several factors examined, bone metastasis, liver metastasis, and the expression level of p-4E-BP1 were shown to have significant impacts on the response to the mTOR inhibitors. Progression-free survival (PFS) was significantly correlated with the expression levels of PTEN and p-4E-BP1 in addition to the presence of bone metastasis on univariate analysis. Of these significant factors, p-4E-BP1 expression and bone metastasis appeared to be independently associated with PFS on multivariate analysis. These findings suggest that it would be useful to consider the expression levels of potential molecular markers in the mTOR signaling pathway, particularly p-4E-BP1, as well as conventional clinical parameters when selecting patients with metastatic RCC who are likely to benefit from treatment with mTOR inhibitors.
Question: What does mTOR stands for?
Answer:
mammalian target of rapamycin