CDKN1B and colorectal carcinoma: No Tier 1 or predicted damaging Tier 2 variants in CTNNB1, PALB2, or STK11 were identified, while a single Tier 1 or damaging Tier 2 variant was detected in AXIN2, CDKN1B, CDKN2A, and SMAD2. Other genes for which a few Tier 1 or damaging Tier 2 variants include GALNT12, NUDT1, PTEN, STK11IP, TGFB1, and TGFBR1. While germline mutations in these genes may play a role in CRC pathogenesis, it is likely limited to very small proportion of cases.