ive ▁and ▁met ast atic ▁potential ▁of ▁m align ant ▁ne op las ms . ▁For ▁example , ▁breast ▁tum or ▁cells ▁det ached ▁from ▁the ▁solid ▁mass ▁gain ▁the ▁ability ▁to ▁in va de ▁l ym ph atic ▁vessels . ▁Currently , ▁two ▁mechan isms ▁are ▁distinguished : ▁ep ith el ial - mes en ch ym al ▁and ▁collect ive - amo eb oid ▁trans itions ▁by ▁which ▁individually ▁migr ating ▁tum or ▁cells ▁are ▁produced ▁( Fig . ▁ 1 ). ▁In ▁turn , ▁the ▁latter , ▁in ▁particular ▁cells ▁that ▁have ▁under g one ▁E MT , ▁are ▁capable ▁under ▁certain ▁conditions ▁of ▁gain ing ▁an ▁ep ith el ial ▁phen ot ype ▁and ▁forming ▁tum or ▁mult ic ell ular ▁complex es . ▁This ▁phen ot ype ▁in version ▁was ▁called ▁the ▁“ mes en ch ym al - ep ith el ial ▁transition ”. <0x09> ▁ <0x09> ▁Ep ith el ial - mes en ch ym al ▁transition <0x09> ▁ <0x09> ▁L ately , ▁there ▁has ▁been ▁vig orous ▁discussion ▁of ▁the ▁ep ith el ial - ▁mes en ch ym al ▁transition ▁as ▁a ▁mechanism ▁during ▁which ▁the ▁tum or ▁cell ▁det aches ▁from ▁the ▁ep ith el ial ▁layer ▁and ▁g ains ▁mot ility ▁( Fig . ▁ 1 ), ▁the ▁so - called ▁“ lo comot or ▁phen ot ype ,” ▁which ▁prom otes ▁invas ive ▁growth ▁and ▁met ast asis . ▁The ▁development ▁of ▁this ▁process ▁as ▁a ▁key ▁factor ▁of ▁cancer ▁pro