```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>Princ-TNM S-22161@11:46:33</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>2</hlevel>
            <item_name>Neoplasms</item_name>
            <item_key>\\i2b2_DIAG\i2b2\Diagnoses\Neoplasms (140-239)\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Diagnoses \ Neoplasms</tooltip>
            <class>ENC</class>
            <constrain_by_modifier>
                <modifier_name>Principal Diagnosis</modifier_name>
                <modifier_key>\\i2b2_DIAG\Principal Diagnosis\</modifier_key>
                <applied_path>\i2b2\Diagnoses\Neoplasms (140-239)\%</applied_path>
            </constrain_by_modifier>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <panel>
        <panel_number>2</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>6</hlevel>
            <item_name>Malignant neoplasm of colon, unspecified</item_name>
            <item_key>\\i2b2_DIAG\i2b2\Diagnoses\Neoplasms (140-239)\Malignant neoplasms (140-208)\Digestive organs and peritoneum (150-159)\(153) Malignant neoplasm of colon\(153-9) Malignant neoplasm of col~\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Diagnoses \ ... \ Malignant neoplasms \ Digestive organs and peritoneum \ Malignant neoplasm of colon \ Malignant neoplasm of colon, unspecified</tooltip>
            <class>ENC</class>
            <constrain_by_modifier>
                <modifier_name>TNM Staging, Distant Metastisis</modifier_name>
                <modifier_key>\\i2b2_DIAG\TNM\Metastisis\</modifier_key>
                <applied_path>\i2b2\Diagnoses\Neoplasms (140-239)\Malignant neoplasms (140-208)\%</applied_path>
            </constrain_by_modifier>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <panel>
        <panel_number>3</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>3</hlevel>
            <item_name>221613_s_at (54469)</item_name>
            <item_key>\\i2b2_EXPR\i2b2\Expression Profiles Data\Affymetrix HG-U133\221613_s_at (54469)\</item_key>
            <item_icon>LA</item_icon>
            <tooltip>Expression Profiles Data\Affymetrix HG-U133\221613_s_at (54469)</tooltip>
            <class>ENC</class>
            <constrain_by_value>
                <value_operator>LT</value_operator>
                <value_constraint>50</value_constraint>
                <value_unit_of_measure>ratio</value_unit_of_measure>
                <value_type>NUMBER</value_type>
            </constrain_by_value>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find patients with a principal diagnosis of neoplasms, specifically malignant neoplasm of the colon, unspecified, who have a TNM staging of distant metastasis, and have an expression profile for the gene 21613_s_at (54669) with a value less than 50.