Inclusion Criteria:

1. age > 18 years old, regardless of gender;

2. patients with previous or current tumor, regardless of tumor type;

3. have a history or current infection with SARS-CoV-2;

4. The vital signs were stable, without severe pulmonary, heart, liver and other
important organ dysfunction;

5. those with good compliance, agreed to participate in this clinical study, receive
corresponding treatment, and signed the informed consent.

Exclusion Criteria:

1. Those who do not meet the inclusion criteria or diagnostic criteria, and cannot
cooperate with blood sampling and arrangement;

2. patients with severe bleeding disorders such as coagulopathy or essential
thrombocytopenia;

3. local skin ulceration affecting blood drawing, severe rash, or infectious diseases;