RAB12 and lung cancer: However, aside from A549 lung cancer cells (50) and RAW264.7 macrophages, shown here, both of which highly express LRRK2 (37, 38), and human peripheral mononuclear blood cells, in which LRRK2 expression was stimulated by TPA and interferon-γ (51), little is known about Rab12 phosphorylation in the absence of hyperactive LRRK2 mutant expression.