Here, we present the first case in literature of a patient affected by advanced PACC with a novel ALK fusion partner, KN Motif And Ankyrin Repeat Domains 4 (KANK4), who achieved a major response under treatment with alectinib….Most importantly, the KANK4-ALK fusion gene identified in this PACC was highly pathogenetic. Treatment with the ALK inhibitor alectinib obtained a radiologic partial response after 2 months of treatment and continued at 4 months.