Acquired On-Target Clinical Resistance Validates FGFR4 as a Driver of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide with no clinically confirmed oncogenic driver. Although preclinical studies implicate the FGF19 receptor FGFR4 in hepatocarcinogenesis, the dependence of human cancer on FGFR4 has not been demonstrated. Fisogatinib (BLU-554) is a potent and selective inhibitor of FGFR4 and demonstrates clinical benefit and tumor regression in patients with HCC with aberrant FGF19 expression.

Simultaneous voltage and calcium imaging and optogenetic stimulation with high sensitivity and a wide field of view.

Transmembrane voltage and intracellular calcium concentration are coupled parameters essential to the function of neurons, cardiomyocytes, and other excitable cells. Here we introduce the microscope for simultaneous optogenetic stimulation and voltage and calcium imaging with fluorescent proteins using three spectrally distinct visible color bands. Firefly-HR combines patterned stimulation, near-total internal reflection laser excitation through a prism located between the sample and a water-immersion objective, and concurrent imaging of three color channels.