Molecular Disease Characterization Initiative (MDCI)

Inclusion Criteria:

* Participant is a candidate for molecular screening for a GlaxoSmithKline (GSK) precision therapeutic clinical study (the Intended Treatment Protocol) that is being conducted in parallel at or nearby the MDCI recruitment site.
* Participant is willing to travel to a site recruiting for the intended GSK treatment protocol (or alternative treatment protocol), if feasible, and if, in the investigator's opinion, the participant would benefit from enrolment into the intended GSK treatment protocol at an alternative clinical site.
* Participants with confirmed advanced/metastatic diagnosis of solid malignancy in one of the following disease-areas: Non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), Breast, ovarian, and colorectal cancer (CRC).
* Participants with life expectancy of greater than (\>) 6 months.
* Participants who are able to provide blood samples.
* Participants who are able to provide an archival formalin-fixed paraffin-embedded (FFPE) tumor specimen from a current lesion/most current setting (from no more than 2 years ago). If an archival tumor specimen is not available, surplus tissue from standard of care procedures is acceptable before fresh biopsy may be obtained.
* Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
* Female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: Is not a woman of childbearing potential (WOCBP) or Is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of less than \[\<\]1 percent \[%\] per year), preferably with low user dependency; A WOCBP must have a negative highly sensitive pregnancy test (urine or serum) as required by local regulations) within 24 hours before tumor biopsy; and if a urine test cannot be confirmed as negative (for example, an ambiguous result), a serum pregnancy test is required. In such cases, the participant must be excluded from participation if the serum pregnancy result is positive.
* The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy.
* Participants capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF).

Exclusion Criteria:

* Participants with Eastern Cooperative Oncology Group (ECOG) Performance Status \>2.
* Participants with history of myocardial infarction, acute inflammatory heart disease, unstable angina, or uncontrolled arrhythmia within the past 6 months.
* For female participants, pregnancy.
* Any serious and/or unstable pre-existing medical, psychiatric disorder or other conditions that could interfere with the participant's safety, obtaining informed consent or compliance to the screening study procedures.