COL6A3 and cancer: Keeping with the example of collagens, the 10 most frequent hydroxylation-affecting PTMmut target largely the same genes (COL1A1, COL3A1, COL5A1 and COL14A1) across the Pan-Cancer cohort with the noticeable addition of COL12A1 in LUSC and UCEC and the lack of COL5A1 in LUAD; conversely, phosphorylation-affecting PTMmut show a distinctive cluster of mutations in collagen VI genes (COL6A2, COL6A3, COL6A5, COL6A6) in UCEC, LUAD, and LUSC, of collagen III, IV, VII, and XXVII (COL3A1, COL4A2, COL7A1, COL27A1) in SCKM and of the fibril-associated collagen XXII (COL22A1) in all of them (Figure S5B).