FOXP1 and aneurysmal bone cyst: However, the subsequent discovery of a predominant expression of shorter FOXP1 isoforms by FOXP1-positive ABC-DLBCL led to the hypothesis that 3p13 translocations targeting the coding region of FOXP1, like t(2;3)(q36;p13), may activate expression of N-terminally truncated isoform(s) of FOXP1 [28], [32].