▁in ▁m amm als ▁now ▁demonstrate ▁an ▁e pid erm al ▁origin . ▁ ▁Function ▁The ▁German ▁an atom ist ▁Friedrich ▁Sig mund ▁Mer kel ▁referred ▁to ▁these ▁cells ▁as ▁T ast z ellen ▁or ▁" touch ▁cells " ▁but ▁this ▁proposed ▁function ▁has ▁been ▁controvers ial ▁as ▁it ▁has ▁been ▁hard ▁to ▁prove . ▁Though , ▁ ▁gen etic ▁knock out ▁m ice ▁have ▁recently ▁shown ▁that ▁Mer kel ▁cells ▁are ▁essential ▁for ▁the ▁special ized ▁coding ▁by ▁which ▁af fer ent ▁n erves ▁resolve ▁fine ▁spatial ▁details . ▁Mer kel ▁cells ▁are ▁sometimes ▁considered ▁A PU D ▁cells ▁( an ▁older ▁definition . ▁More ▁commonly ▁class ified ▁as ▁a ▁part ▁of ▁dispers ed ▁ne uro end ocr ine ▁system ) ▁because ▁they ▁contain ▁dense ▁core ▁gran ules , ▁and ▁thus ▁may ▁also ▁have ▁a ▁ne uro end ocr ine ▁function . ▁ ▁Sub ject ▁to ▁m align ancy ▁Although ▁un common , ▁these ▁cells ▁may ▁become ▁m align ant ▁and ▁form ▁a ▁Mer kel ▁cell ▁car cin oma — an ▁ag gress ive ▁and ▁difficult ▁to ▁treat ▁skin ▁cancer . ▁ ▁See ▁also ▁▁▁ ▁Mer kel ▁n erve ▁ending ▁ ▁Mer kel ▁cell ▁car cin oma ▁ ▁List ▁of ▁ker at ins ▁expressed ▁in ▁the ▁human ▁inte g ument ary ▁system ▁ ▁List ▁of ▁human ▁cell ▁types ▁derived ▁from ▁the ▁germ ▁layers ▁ ▁References ▁ ▁External ▁links ▁ ▁N IF ▁Search ▁- ▁Mer ck el ▁Disc ▁Cell ▁via ▁the ▁Neu ros cience ▁Information ▁Framework ▁ ▁Category : N erv ous ▁t