sentence: XERcomp and W2-EEQ were associated mostly with Factor 1 , which was influenced mainly by the perfluorinated carboxylates PFNA , PFOA , and PFDA plus the perfluorinated sulfonate PFOS , whereas XER was most convincingly associated with Factor 3 , which was primarily influenced by PFUnA , PFDA , and PFNA ( all perfluorinated carboxylates ) .