What statistical test could the scientists have used to determine whether there was a significant relationship between the amount of CD20 on the surface of B cells and the percentage of B cells destroyed by Rituximab?

Give a reason for your answer.

Name of test

Reason

From these data, what can you conclude about the effectiveness of Rituximab in treating patients with CLL?

Do not include considerations of statistical analyses in your answer.

Approximately 11 percent of people with CLL also have mutations of a gene called NOTCH1. This leads to production of a non-functional transcription factor associated with CD20 production.

The doctors determined the median percentage of B cells destroyed by Rituximab in people with CLL who had the NOTCH1 mutation and those who did not.

The doctors' results are shown in Table 1.

Human blood contains (approximately) 1.0 × 109 B cells per dm3.

Use the median values in Table 1 to calculate the difference between the number of B cells per dm3 in the blood of people treated with Rituximab with the NOTCH1 mutation and people without the NOTCH1 mutation.

Express your answer in standard form. Show your working.

Answer ______________ cells per dm3

Use all of the information to suggest how the mutation of NOTCH1 led to the difference in the percentage of B cells destroyed by Rituximab.