For the reader's convenience, a user-friendly and publicly accessible web-server named 2L-piRNA has been established. Here, a step-by-step guide on how to use the webserver to get a desired result without the need to carefully understand the mathematical details.

  Step 1. Open the web-server at http://bliulab.net/2L-piRNA/ and you will see its top page of 2L-piRNA. Click on the ReadMe button to see a brief introduction about the server and the caveat when using it.

  Step 2. You can either type or copy and paste the query sequences into the input box. You can also directly upload your input data via the Browse button. The input sequence should be in the FASTA format. For the examples of sequences in the FASTA format, click the Example button right above the input box.

  Step 3. Click on the Submit button to see the predicted results. For example, if you use the four query RNA sequences in the Example window as the input, you will see on your computer screen that the 1st and 2nd query sequences are of non-piRNA. The 3rd one is of piRNA with the function for instructing target mRNAs deadenylation. The 4th one is of piRNA but without that function.