Connective Tissue Disease, also known as abnormality of connective tissue, is related to collagen disease and marfan syndrome, and has symptoms including back pain, muscle cramp and sciatica. An important gene associated with Connective Tissue Disease is FBN1 (Fibrillin 1), and among its related pathways/superpathways are ERK Signaling and Integrin Pathway. The drugs Angiotensin II and Sirolimus have been mentioned in the context of this disorder. Affiliated tissues include skin and bone, and related phenotypes are nervous system and homeostasis/metabolism