Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Let me give you an example: In 1582 the united provinces invited francis, duke of anjou to lead them; but after a failed attempt to take antwerp in 1583, the duke left the netherlands again. after the assassination of william of orange (10 july 1584), both henry iii of france and elizabeth i of england declined the offer of sovereignty. however, the latter agreed to turn the united provinces into a protectorate of england (treaty of nonsuch, 1585), and sent the earl of leicester as governor-general. this was unsuccessful and in 1588 the provinces became a confederacy. the union of utrecht is regarded as the foundation of the republic of the seven united provinces, which was not recognized by the spanish empire until the peace of westphalia in 1648.
The answer to this example can be: In what year did francis, duke of anjou leave the netherlands?
Here is why: The generated question is perfect. Because the question is based on second sentence of the input passage and its answer is 1583.

OK. solve this:
Somatic mutations in the epidermal growth factor receptor (EGFR) gene are associated with the responses to the tyrosine kinase inhibitors gefitinib and erlotinib in patients with non-small-cell lung cancer (NSCLC). Although various methods for detecting EGFR gene mutations have been developed, they have several disadvantages. We attempted to establish a new method for the detection of EGFR gene mutations with the use of paraffin-embedded samples. The detections of T790M mutations in exon 20 and L858R mutations in exon 21 are based on the principle of allele-specific oligonucleotide polymerase chain reaction (PCR). We also designed PCR primers that enable to detect all types of deletions in exon 19. We assessed the basic performance efficiency of this method, and to confirm its clinical applicability, we performed PCR using DNA extracted from 66 tissue sections that were obtained from patients with NSCLC and embedded in paraffin. The sensitivity of this method for the detection of deletions or mutations was as low as 0.5%. In the 66 subjects whose samples were analyzed, we detected the following deletions and mutations in the EGFR gene: 11 deletions in exon 19, 8 L858R mutations, and 1 double mutation of L858R and T790M. The present method is sensitive and specific for the detection of deletions and mutations in the EGFR gene and is thus suitable for use in laboratory tests.
Answer:
Mutations in which gene determine response to both erlotinib and gefitinib?