ized ▁by ▁fast ▁de form ability , ▁ad a ption ▁of ▁their ▁shapes ▁to ▁existing ▁structures ▁of ▁the ▁surrounding ▁ext rac ell ular ▁matrix , ▁and ▁pen etr ation ▁through ▁them ▁via ▁narrow ▁spaces ▁in ▁a ▁com pressed ▁form . ▁Mov ement ▁and ▁re location ▁are ▁carried ▁out ▁through ▁success ive ▁high - speed ▁cycles ▁of ▁expansion ▁and ▁contra ction ▁of ▁the ▁cell ’ s ▁body ▁with ▁the ▁development ▁of ▁“ ble b - like ” ▁pro tr us ions ▁of ▁the ▁cell ▁memb rane . ▁These ▁ble bs ▁allow ▁the ▁cell ▁to ▁investigate ▁the ▁micro environment ▁to ▁find ▁the ▁most ▁suitable ▁route ▁of ▁movement ▁to ▁by pass ▁various ▁obst acles , ▁where by ▁tum or ▁cells ▁are ▁capable ▁of ▁moving ▁through ▁narrow ▁g aps ▁in ▁the ▁ext rac ell ular ▁matrix . ▁Develop ing ▁changes ▁in ▁the ▁cell ▁shape ▁are ▁generated ▁by ▁the ▁cort ical ▁act in ▁c yt os ke leton ▁that ▁is , ▁in ▁turn , ▁controlled ▁by ▁small ▁G TP ase ▁R ho A ▁and ▁its ▁effect or , ▁RO CK ▁kin ase . ▁This ▁G TP ase ▁belongs ▁to ▁the ▁super family ▁of ▁small ▁G TP ▁hyd rol ases , ▁whose ▁members ▁play ▁key ▁roles ▁in ▁the ▁am o eb oid ▁type ▁of ▁invasion , ▁since ▁they ▁are ▁involved ▁in ▁signal ▁trans du ction ▁and , ▁thereby , ▁in ▁the ▁reg ulation ▁of ▁a ▁wide ▁variety ▁of ▁processes ▁occurr ing ▁in ▁the ▁cell , ▁including ▁re organ ization ▁of ▁the ▁act in ▁c yt os ke leton ▁during