( They ( ( are ( ( ( ( ( ( Basal ( Cell Carcinoma ) ) , ) ( which ( accounts ( for ( ( ( approximately 90 ) percent ) ( of ( ( skin cancers ) ( in ( the U.S. ) ) ) ) ) ) ) ) ) , ) and ) ( ( ( Squamous ( Cell Carcinoma ) ) , ) ( ( the ( second ( ( most common ) form ) ) ) ( of ( skin cancer ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP are) (NP (NP (NP (NNP Basal) (NNP Cell) (NNP Carcinoma)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ accounts) (PP (IN for) (NP (NP (QP (RB approximately) (CD 90)) (NN percent)) (PP (IN of) (NP (NP (NN skin) (NNS cancers)) (PP (IN in) (NP (DT the) (NNP U.S.))))))))))) (, ,) (CC and) (NP (NP (NNP Squamous) (NNP Cell) (NNP Carcinoma)) (, ,) (NP (NP (DT the) (JJ second) (ADJP (RBS most) (JJ common)) (NN form)) (PP (IN of) (NP (NN skin) (NN cancer))))))) (. .)))
They are Basal Cell Carcinoma, which accounts for approximately 90 percent of skin cancers in the U.S., and Squamous Cell Carcinoma, the second most common form of skin cancer.
(ROOT (S (NP (JJ Squamous) (NN cell) (NN carcinoma)) (VP (VBZ is) (NP (DT the) (JJ second) (ADJP (RBS most) (JJ common)) (NN skin) (NN cancer))) (. .)))