▁domains . ▁The ▁prote ins ▁medi ate ▁signal ▁trans du ction ▁events ▁that ▁play ▁a ▁role ▁in ▁the ▁reg ulation ▁of ▁cell ▁development , ▁activation , ▁growth ▁and ▁mot ility . ▁This ▁encoded ▁protein ▁is ▁a ▁cell ▁surface ▁g ly cop rote in ▁that ▁is ▁known ▁to ▁complex ▁with ▁integr ins . ▁This ▁protein ▁appears ▁to ▁promote ▁mus cle ▁cell ▁fusion ▁and ▁support ▁my ot ube ▁maintenance . ▁Also ▁it ▁may ▁be ▁involved ▁in ▁signal ▁trans du ction . ▁This ▁gene ▁is ▁local ized ▁in ▁the ▁tum or - supp ress or ▁gene ▁region ▁and ▁thus ▁it ▁is ▁a ▁candidate ▁gene ▁for ▁m align an cies . ▁ ▁The ▁t et ras pan in ▁family ▁includes ▁CD 9 , ▁CD 3 7 , ▁CD 5 3 , ▁CD 6 3 , ▁CD 8 1 ▁( this ▁protein ), ▁CD 8 2 ▁and ▁CD 1 5 1 . ▁ ▁CD 8 1 ▁interact s ▁directly ▁with ▁imm un og lob ul in ▁super family ▁member ▁ 8 ▁( IG SF 8 , ▁CD 3 1 6 ) ▁and ▁CD 3 6 . ▁It ▁forms ▁a ▁signal ▁trans du ction ▁complex ▁with ▁CD 1 9 , ▁CD 2 1 ▁and ▁Le u - 1 3 ▁( CD 2 2 5 ) ▁on ▁the ▁surface ▁of ▁the ▁B ▁cell . ▁ ▁On ▁T ▁cells ▁CD 8 1 ▁associ ates ▁with ▁CD 4 ▁and ▁CD 8 ▁and ▁provides ▁a ▁cost im ul atory ▁signal ▁with ▁CD 3 . ▁ ▁C lin ical ▁significance ▁▁ ▁This ▁protein ▁plays