 Patients with ALPS have a defect in this apoptotic pathway, leading to chronic non-malignant lymphoproliferation, autoimmune disease, and secondary cancers.All people with ALPS have signs of lymphoproliferation, which makes it the most common clinical manifestation of the disease.The increased proliferation of lymphoid cells can cause the size of lymphoid organs such as the lymph nodes and spleen to increase (lymphadenopathy and splenomegaly, present in respectively over 90% and over 80% of patients).