dbPTM in 2019: exploring disease association and cross-talk of post-translational modifications. - Kai-Yao Huang; Tzong-Yi Lee; Hui-Ju Kao; Chen-Tse Ma; Chao-Chun Lee; Tsai-Hsuan Lin; Wen-Chi Chang; Hsien-Da Huang (Nucleic Acids Res., 2019)