Whereas the straightness in the movement of ALK+ ALCL cell lines was heterogeneous, with high straightness in SU‐DHL‐1 cells (0.34) and lower straightness in DEL cells (0.19), ALK− ALCL and T‐cell‐derived cHL cell lines both had significantly lower straightness (0.20 and 0.10 in ALK− ALCL vs 0.19 and 0.13 in T‐cell‐derived cHL cells; one‐way ANOVA with Bonferroni ́s post‐test for multiple comparisons; Figure 2A), which means that the cells frequently turned forward and backward, a pattern that may resemble the antigen‐scanning activity of normal T cells. The gene discussed is ALK; the disease is anaplastic large cell lymphoma.