PLXs

PLXs is a term that can refer to several distinct concepts across biology and pharmacology, depending on the field and context. The most common uses are in reference to plexin receptors in biology and to Plexxikon-derived small-molecule compounds in drug research.

In biology, PLX is often used as a shorthand prefix for the Plexin family of transmembrane receptors, with members such as PLXNA1, PLXNB1, PLXNC1, and related genes. Plexins participate in semaphorin signaling and play key roles in axon guidance, neuronal migration, and vascular and immune cell behavior. They typically have an extracellular sema domain, multiple auxiliary domains, a transmembrane region, and a cytoplasmic GAP-like domain that helps regulate cytoskeletal dynamics through Rho family GTPases. Plexin signaling often involves interactions with neuropilins and semaphorins, and dysregulation has been linked to neurodevelopmental disorders and cancer.

In pharmacology, PLX can denote compounds developed by the biotech company Plexxikon, which used PLX-prefixed codes for several research inhibitors. Notable examples include PLX4032, a BRAF inhibitor known in clinical development as vemurafenib for BRAF-mutant melanoma, and PLX4720, a related research compound. PLX3397, another Plexxikon compound, progressed in development as a CSF1R inhibitor (pexidartinib) and has been studied for conditions involving macrophage activity. These PLX compounds are primarily used as research tools or clinical candidates and are not universally approved in their original codes.

See also Plexin; Plexxikon; semaphorin signaling.