EGFR and neoplasm: Some researchers found that fluoxetine could suppress EGFR signaling, a feature that other kinds of SSRIs do not present.8 In the GBM39 mouse model, fluoxetine at human-equivalent doses of 50 and 80 mg/day significantly inhibited tumor growth and prolonged survival in a dose-dependent manner, whereas a low dose equivalent to 20 mg/day did not affect tumor growth.