6 ▁Summer ▁Olympics ▁Category : A th let es ▁( track ▁and ▁field ) ▁at ▁the ▁ 2 0 1 0 ▁Summer ▁Youth ▁Olympics ▁Category : World ▁Athletics ▁Championships ▁athlet es ▁for ▁Mor oc co <0x0A> </s> ▁NK G 2 - F ▁type ▁II ▁integral ▁memb rane ▁protein ▁is ▁a ▁protein ▁that ▁in ▁humans ▁is ▁encoded ▁by ▁the ▁K L RC 4 ▁gene . ▁ ▁Natural ▁k iller ▁( N K ) ▁cells ▁are ▁l ym ph ocy tes ▁that ▁can ▁medi ate ▁l ysis ▁of ▁certain ▁tum or ▁cells ▁and ▁virus - in fect ed ▁cells ▁without ▁previous ▁activation . ▁They ▁can ▁also ▁reg ulate ▁specific ▁hum oral ▁and ▁cell - medi ated ▁imm unity . ▁NK ▁cells ▁prefer entially ▁express ▁several ▁calci um - dependent ▁( C - type ) ▁lect ins , ▁which ▁have ▁been ▁imp licated ▁in ▁the ▁reg ulation ▁of ▁NK ▁cell ▁function . ▁K L RC 4 ▁is ▁a ▁member ▁of ▁the ▁NK G 2 ▁group ▁which ▁are ▁expressed ▁primarily ▁in ▁natural ▁k iller ▁( N K ) ▁cells ▁and ▁enc odes ▁a ▁family ▁of ▁transm emb rane ▁prote ins ▁character ized ▁by ▁a ▁type ▁II ▁memb rane ▁orientation ▁( ext rac ell ular ▁C ▁termin us ) ▁and ▁the ▁presence ▁of ▁a ▁C - type ▁lect in ▁domain . ▁The ▁NK G 2 ▁gene ▁family ▁is ▁located ▁within ▁the ▁NK ▁complex , ▁a ▁region ▁that ▁contains ▁several ▁C - type ▁lect in ▁gen es ▁prefer entially ▁expressed ▁on ▁NK ▁cells . ▁The ▁ 3 ' ▁end