COL18A1 and acute lymphoblastic leukemia: Western blotting of the precipitated proteins with three different antibodies to human collagen XVIII (anti-ALL, anti-LONG and anti-endostatin) revealed a main 120 kDa band, which is presumably derived from the middle variant of collagen, containing the N-terminus and the collagenous central part of the molecule but lacking the endostatin domain (Figure 5 and data not shown).