A multi-level memory cell capable of storing two or three bits of digital data occupies only four lithographic squares and requires only one or two logic level voltage sources, respectively. A first aspect allows detecting a user contact swipe motion in a predetermined direction along said keyboard, scrolling said keyboard across said display in accordance with said motion, and stopping said scrolling upon termination of user contact swipe motion. The holder is provided with holding members for holding and fixing the package of the mounting component and lead holes for guiding the lead to a through hole of the circuit substrate. The above combinatorial, high-throughput method of screening candidate coat materials results in a substantial increase in the discovery rate of new coating materials. Thereby, tones and smoothing can be represented suitably, by means of a small number of different waveforms. Certain aspects of the invention are directed to preparations of hedgehog polypeptides, agonists, antagonists, or other molecules which regulate patched or smoothened signalling, and their uses as immunomodulatory agents.