B-cell lymphoma-extra large (Bcl-xl) is a transmembrane molecule in the mitochondria. It is involved in the signal transduction

Signal transduction

Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...

 pathway of the FAS-L. It is one of several anti-apoptotic proteins which are members of the Bcl-2 family

Bcl-2 family

Apoptosis regulator Bcl-2, BH is a family of evolutionarily related proteins. These proteins govern mitochondrial outer membrane permeabilization and can be either pro-apoptotic or anti-apoptotic...

 of proteins. It has been implicated in the survival of cancer cells. Other Bcl-2 proteins include Bcl-2

Bcl-2

Bcl-2 is the founding member of the Bcl-2 family of apoptosis regulator proteins encoded by the BCL2 gene. Bcl-2 derives its name from B-cell lymphoma 2, as it is the second member of a range of proteins initially described in chromosomal translocations involving chromosomes 14 and 18 in...

, Bcl-w, Bcl-xs, and Mcl-1.