Health care stocks were mostly lower this afternoon, with the NYSE Health Care Index sinking 1.6% while the SPDR Health Care Select Sector ETF (XLV) was down 2.0%. The Nasdaq Biotechnology index also was sinking 2.1%. In company news, Matinas BioPharma Holdings (MTNB) rose 21% after announcing an exclusive research agreement with German genetic therapies company BioNTech (BNTX) to evaluate a combination of mRNA formats and Matinas' lipid nanocrystal platform technology.