Shares of Illumina Inc. /zigman2/quotes/203509482/composite ILMN -0.85% fell more than 13% in the late session after the biotech company reported second-quarter results shy of Wall Street expectations and said many of its research clients remain closed due to the pandemic. Illumina said it gained $47 million, or 32 cents a share, in the quarter, compared with $296 million, or $1.99 a share, for the second quarter of 2019. Adjusted for one-time items, Illumina earned $92 million, or 62 cents a share, compared with $200 million, or $1.35 a share, a year ago. Revenue fell 25% to $633 million. Analysts polled by FactSet had expected the company to report adjusted EPS of 67 cents on sales of $679 million. "As expected, the second quarter was significantly impacted by pandemic-related disruption in our customers' operations and was particularly challenging for many of our research customers who remain closed or operating at limited scale," Chief Executive Francis deSouza said in a statement. Illumina said it continues to forgo fiscal 2020 guidance "due to the uncertainties around the severity and duration of the COVID-19 pandemic." It ended the quarter with free cash flow of $202 million, compared with $96 million in the second quarter of 2019. Shares of Illumina ended the regular trading day down 0.4%.