( Keratinocytes ( ( form ( at ( ( the ( bottom layer ) ) ( of ( the epidermis ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Keratinocytes)) (VP (VBP form) (PP (IN at) (NP (NP (DT the) (JJ bottom) (NN layer)) (PP (IN of) (NP (DT the) (NNS epidermis)))))) (. .)))
Keratinocytes form at the bottom layer of the epidermis.
(ROOT (S (NP (NNS Melanocytes)) (VP (VBP are) (VP (VBN located) (PP (IN in) (NP (NP (DT the) (JJ bottom) (NN layer)) (PP (IN of) (NP (DT the) (NNS epidermis))))))) (. .)))