You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

ACE2 has been established as the main receptor for SARS-CoV-2. Since other human coronaviruses are known to use co-receptors for viral cell entry, it has been suggested that DPP4 (CD26) could be a potential additional binding target or co-receptor, supported by early molecular docking simulation studies. However, recent biophysical studies have shown this interaction to be very weak. We have conducted detailed molecular docking simulations to predict the potential binding interactions between the receptor binding domain (RBD) of the spike protein of SARS-CoV-2 and DPP4 and compare them with the interactions observed in the experimentally determined structure of the complex of MERS-CoV with DPP4. Whilst the overall binding mode of the RBD of SARS-CoV-2 to DPP4 is predicted to be similar to that observed in the MERS-CoV-DPP4 complex, including a number of equivalent interactions, important differences in the amino acid sequences of SARS-CoV-2 and MERS-CoV result in substantially weakened interactions with DPP4. This is shown to arise from differences in the predicted proximity, nature and secondary structure at the binding interface on the RBD of SARS-CoV-2. These findings do not support DPP4 being a significant receptor for SARS-CoV-2.
["Mechanism", "Treatment"]