Here are a few recent titles with links to articles:
Lichen secondary metabolites are responsible for induction of apoptosis in HT-29 and A2780 human cancer cell lines
Usnic acid inhibits breast tumor angiogenesis and growth by suppressing VEGFR2-mediated AKT and ERK1/2 signaling pathways
Usnic acid inhibits growth and induces cell cycle arrest and apoptosis in human lung carcinoma a549 cells
It will be fascinating to see where this might lead!