the aligned sequence of CCDC42B with 2I1K_A. Predicted structure (blue: not similar residues, red: conserved residues, gray: not aligned CCDC42B residues with 2I1K_A). Expression Human Protein atlas resulted in CCDC42B expression in normal human tissue. The expression level of CCDC42B gene in human normal tissues was detected at high to moderate level in 17 out of 78 tissues analyzed using Expressed Sequence Tag (EST) technique. CCDC42B gene has a narrowed expression in tissues. The gene has higher expression in respiratory epithelia and fallopian tube; Moderate expression in intestine and liver; and low to none expression in other normal tissues. Moreover, Microarray and Immunohistochemistry (IHC) expression detected presence of low level of CCDC42B mRNA expression in: salivary gland, stomach, skin, bone marrow, and lung. Coiled coil domain containing 42B is involved in cancer; CCDC42B gene is expressed in low to moderate level in tumor cell. Promoter and Transcription Binding Factors According to Genomatix, the Promoter region contains 859 base pairs and it is located on the positive strand of chromosome 12 from region 113,586,906 to 113,587,764 upstream of CCDC42B gene. The promoter region was predicted to contain sites for transcription binding factors that regulate expression of CCDC42B. The Attached image illustrate important transcription binding factors in the promoter region for human CCDC42B . Expression CCDC42B gene has a narrowed expression in tissues. The gene has higher expression in respiratory epithelia and fallopian tube; Moderate expression in intestine and liver; low to none expression in other normal tissues. Coiled coil domain containing 42B is involved in some types of cancer. CCDC42B gene is expressed in low to moderate level in tumor cell. Function / Biochemistry According to year 2014, CCDC42B gene/protein has unknown function in homo sapiens. However, Human CCDC42B is predicted to be involved in flagella assembly and motility. Interacting Proteins According to STRING, MINT, and IntAct, Human CCDC42B did not show any direct interaction with other proteins. Searching GeneMania, other interactions have been identified by co-expression with other proteins as seen in the figure. CCDC42B was found to co-express with other coiled-coil domains containing proteins (CCDC78 and CCDC153). Since Human CCDC42B is expressed in low level in testis, it is predicted that human to interact with SPATC1 (Spermatogenesis and centriole associated 1). Clinical Significance Disease Association Human CCDC42B is located at chromosome 12 (12q24.13), which is linked to skeletal deformities, hypochondrogenesis, achondrogenesis, and kniest dysplasia. According to OMIM search chromosome