FACS or FaCS may refer to:
DHR2 (DOCK homology region 2), also known as CZH2 or Docker2, is a protein domain of approximately 450-550 amino acids that is present in the DOCK family of proteins. This domain functions as a guanine nucleotide exchange factor (GEF) domain for small G proteins of the Rho family. DHR2 domains bear no significant similarity to the well described DH domain (Dbl homologous domain) present in other RhoGEFs such as Vav, P-Rex and TRIO. Indeed, the most divergent mammalian DHR2 domains share only 16-17% sequence similarity.
DHR1 (DOCK homology region 1), also known as CZH1 or Docker1, is a protein domain of approximately 200-250 amino acids that is present in the DOCK family of signalling proteins. This domain binds phospholipids and so may assist in recruitment to cellular membranes. There is evidence that this domain may also mediate protein-protein interactions.
DHR Locomotive number 778 was built for the Darjeeling Himalayan Railway. Nicknamed the "Toy Train", the railway is a 2 ft (610 mm) gauge narrow-gauge railway from Siliguri to Darjeeling in West Bengal, run by the Indian Railways.
DHR 778 is a 0-4-0ST B Class, a design built between 1889 and 1927. A total of 34 were built. By 2005 only 12 remained on the railway and in use (or under repair). The B class locomotives were designed by Sharp Stewart & Co. of Glasgow and built by them, their successors North British Locomotive Company (NBL, Glasgow), and three each by Baldwin Locomotive Works (BLW, Philadelphia, USA), and the DHR works at Tindharia.
Number 778 (originally No.19) was built in 1889 by Sharp Stewart & Co at the Atlas Works in Glasgow. It is the only DHR locomotive that has been taken out of India. After many years out of use at the Hesston Steam Museum, it was sold to enthusiast Adrian Shooter in the United Kingdom and restored to working order. As of 2009, it is based on Beeches, a private railway in Oxfordshire, and has also run on the Ffestiniog Railway, the Leighton Buzzard Light Railway and the Launceston Steam Railway.