NL4

NL4 is an acronym that can refer to several things depending on context. The most widely cited usage in scientific literature is related to the HIV-1 molecular clone NL4-3, a laboratory-adapted strain used as a reference in virology research. In this context, NL4-3 denotes a full-length infectious clone of HIV-1 that is frequently studied in cell culture to investigate viral replication, entry, and responses to antiretroviral drugs. The clone is propagated from the plasmid pNL4-3 and has become a standard in many assays, contributing to characterizing envelope-receptor interactions and drug susceptibility, while requiring appropriate biosafety measures.

In other settings, NL4 may appear as an acronym or model designation that is not standardized. It can occur as part of product codes, project names, or naming conventions adopted by organizations, where the precise meaning is defined by the issuing entity. Because NL4 has no single universal definition, readers should rely on context such as accompanying descriptions and documentation to interpret its intended meaning.

See also NL4-3, HIV-1 molecular clone, pNL4-3.