In two patients with autoimmune lymphoproliferative syndrome (ALPS), the abnormal splicing of exon 6 of FAS, which encodes the part of the protein that localizes in the plasma membrane and allows the FAS protein to act as a signal between the environment and the cell, was shown to be present due to the reduced expression of SRSF4 [6]. The gene discussed is SRSF4; the disease is autoimmune lymphoproliferative syndrome.