ALK and lung lymphoma: Next, to reveal when L1196M ALK mutation emerged in lymphoma cells over time, ddPCR analysis using an L1196M ALK mutation detection probe set (LBx Probe ALK L1196M (A071); Riken Genesis, Tokyo, Japan) was performed for each of the blood cell samples preserved over time and the pulmonary lymphoma sample at the second relapse (Figure 1).